Provided by: curl_7.58.0-2ubuntu3.24_amd64 bug

NAME

       curl - transfer a URL

SYNOPSIS

       curl [options] [URL...]

DESCRIPTION

       curl  is  a  tool to transfer data from or to a server, using one of the supported protocols (DICT, FILE,
       FTP, FTPS, GOPHER, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, POP3, POP3S, RTMP, RTSP, SCP, SFTP, SMB,  SMBS,
       SMTP, SMTPS, TELNET and TFTP). The command is designed to work without user interaction.

       curl  offers  a  busload of useful tricks like proxy support, user authentication, FTP upload, HTTP post,
       SSL connections, cookies, file transfer resume, Metalink, and more. As you will see below, the number  of
       features will make your head spin!

       curl is powered by libcurl for all transfer-related features. See libcurl(3) for details.

URL

       The URL syntax is protocol-dependent. You'll find a detailed description in RFC 3986.

       You can specify multiple URLs or parts of URLs by writing part sets within braces as in:

         http://site.{one,two,three}.com

       or you can get sequences of alphanumeric series by using [] as in:

         ftp://ftp.example.com/file[1-100].txt

         ftp://ftp.example.com/file[001-100].txt    (with leading zeros)

         ftp://ftp.example.com/file[a-z].txt

       Nested sequences are not supported, but you can use several ones next to each other:

         http://example.com/archive[1996-1999]/vol[1-4]/part{a,b,c}.html

       You  can  specify  any amount of URLs on the command line. They will be fetched in a sequential manner in
       the specified order.

       You can specify a step counter for the ranges to get every Nth number or letter:

         http://example.com/file[1-100:10].txt

         http://example.com/file[a-z:2].txt

       When using [] or {} sequences when invoked from a command line prompt, you probably have to put the  full
       URL within double quotes to avoid the shell from interfering with it. This also goes for other characters
       treated special, like for example '&', '?' and '*'.

       Provide the IPv6 zone index in the URL with an escaped percentage sign and the interface name. Like in

         http://[fe80::3%25eth0]/

       If  you  specify URL without protocol:// prefix, curl will attempt to guess what protocol you might want.
       It will then default to HTTP but try other protocols based on often-used host name prefixes. For example,
       for host names starting with "ftp." curl will assume you want to speak FTP.

       curl will do its best to use what you pass to it as a  URL.  It  is  not  trying  to  validate  it  as  a
       syntactically correct URL by any means but is instead very liberal with what it accepts.

       curl  will attempt to re-use connections for multiple file transfers, so that getting many files from the
       same server will not do multiple connects / handshakes. This improves speed. Of course this is only  done
       on files specified on a single command line and cannot be used between separate curl invokes.

PROGRESS METER

       curl  normally  displays  a  progress meter during operations, indicating the amount of transferred data,
       transfer speeds and estimated time left, etc. The progress meter displays number of bytes and the  speeds
       are in bytes per second. The suffixes (k, M, G, T, P) are 1024 based. For example 1k is 1024 bytes. 1M is
       1048576 bytes.

       curl  displays  this  data to the terminal by default, so if you invoke curl to do an operation and it is
       about to write data to the terminal, it disables the progress meter as otherwise it  would  mess  up  the
       output mixing progress meter and response data.

       If you want a progress meter for HTTP POST or PUT requests, you need to redirect the response output to a
       file, using shell redirect (>), -o, --output or similar.

       It  is  not  the  same  case  for FTP upload as that operation does not spit out any response data to the
       terminal.

       If you prefer a progress "bar" instead of the regular meter, -#, --progress-bar is your friend.  You  can
       also disable the progress meter completely with the -s, --silent option.

OPTIONS

       Options start with one or two dashes. Many of the options require an additional value next to them.

       The  short "single-dash" form of the options, -d for example, may be used with or without a space between
       it and its value, although a space is a recommended separator. The long "double-dash"  form,  -d,  --data
       for example, requires a space between it and its value.

       Short  version  options that don't need any additional values can be used immediately next to each other,
       like for example you can specify all the options -O, -L and -v at once as -OLv.

       In general, all boolean options are enabled with --option and yet again disabled with  --no-option.  That
       is,  you  use  the  exact same option name but prefix it with "no-". However, in this list we mostly only
       list and show the --option version of them.  (This  concept  with  --no  options  was  added  in  7.19.0.
       Previously most options were toggled on/off on repeated use of the same command line option.)

       --abstract-unix-socket <path>
              (HTTP)  Connect  through  an  abstract  Unix  domain  socket, instead of using the network.  Note:
              netstat shows the path of an abstract socket prefixed with '@', however the <path> argument should
              not have this leading character.

              Added in 7.53.0.

       --anyauth
              (HTTP) Tells curl to figure out authentication method by itself, and use the most secure  one  the
              remote  site  claims  to support. This is done by first doing a request and checking the response-
              headers, thus possibly inducing an extra network round-trip. This is used  instead  of  setting  a
              specific authentication method, which you can do with --basic, --digest, --ntlm, and --negotiate.

              Using  --anyauth  is not recommended if you do uploads from stdin, since it may require data to be
              sent twice and then the client must be able to rewind. If the need  should  arise  when  uploading
              from stdin, the upload operation will fail.

              Used together with -u, --user.

              See also --proxy-anyauth and --basic and --digest.

       -a, --append
              (FTP  SFTP)  When  used  in  an  upload,  this  makes  curl  append  to the target file instead of
              overwriting it. If the remote file doesn't exist, it will be created.   Note  that  this  flag  is
              ignored by some SFTP servers (including OpenSSH).

       --basic
              (HTTP)  Tells  curl to use HTTP Basic authentication with the remote host. This is the default and
              this option is usually pointless, unless you use it to override a previously set option that  sets
              a different authentication method (such as --ntlm, --digest, or --negotiate).

              Used together with -u, --user.

              See also --proxy-basic.

       --cacert <file>
              (TLS)  Tells  curl  to use the specified certificate file to verify the peer. The file may contain
              multiple CA certificates. The certificate(s) must be in PEM format. Normally curl is built to  use
              a default file for this, so this option is typically used to alter that default file.

              curl  recognizes  the environment variable named 'CURL_CA_BUNDLE' if it is set, and uses the given
              path as a path to a CA cert bundle. This option overrides that variable.

              The windows version of  curl  will  automatically  look  for  a  CA  certs  file  named  ´curl-ca-
              bundle.crt´,  either in the same directory as curl.exe, or in the Current Working Directory, or in
              any folder along your PATH.

              If curl is built against the NSS SSL library, the NSS PEM PKCS#11 module (libnsspem.so)  needs  to
              be available for this option to work properly.

              (iOS  and macOS only) If curl is built against Secure Transport, then this option is supported for
              backward compatibility with other SSL engines, but it should not be set. If the option is not set,
              then curl will use the certificates in the system and user Keychain to verify the peer,  which  is
              the preferred method of verifying the peer's certificate chain.

              If this option is used several times, the last one will be used.

       --capath <dir>
              (TLS) Tells curl to use the specified certificate directory to verify the peer. Multiple paths can
              be  provided  by separating them with ":" (e.g.  "path1:path2:path3"). The certificates must be in
              PEM format, and if curl is built against OpenSSL, the directory must have been processed using the
              c_rehash utility supplied with OpenSSL. Using --capath can allow OpenSSL-powered curl to make SSL-
              connections much more efficiently than using --cacert  if  the  --cacert  file  contains  many  CA
              certificates.

              If  this option is set, the default capath value will be ignored, and if it is used several times,
              the last one will be used.

       --cert-status
              (TLS) Tells curl to verify the status of the server certificate by using  the  Certificate  Status
              Request (aka. OCSP stapling) TLS extension.

              If this option is enabled and the server sends an invalid (e.g. expired) response, if the response
              suggests  that  the  server  certificate  has been revoked, or no response at all is received, the
              verification fails.

              This is currently only implemented in the OpenSSL, GnuTLS and NSS backends.

              Added in 7.41.0.

       --cert-type <type>
              (TLS) Tells curl what certificate type the provided certificate  is  in.  PEM,  DER  and  ENG  are
              recognized types.  If not specified, PEM is assumed.

              If this option is used several times, the last one will be used.

              See also -E, --cert and --key and --key-type.

       -E, --cert <certificate[:password]>
              (TLS) Tells curl to use the specified client certificate file when getting a file with HTTPS, FTPS
              or  another  SSL-based  protocol.  The  certificate  must  be  in  PKCS#12  format if using Secure
              Transport, or PEM format if using any other engine.  If the optional password isn't specified,  it
              will  be  queried  for on the terminal. Note that this option assumes a "certificate" file that is
              the private key and the client certificate concatenated! See -E, --cert and --key to specify  them
              independently.

              If  curl  is  built against the NSS SSL library then this option can tell curl the nickname of the
              certificate to use within the NSS database defined by the  environment  variable  SSL_DIR  (or  by
              default  /etc/pki/nssdb). If the NSS PEM PKCS#11 module (libnsspem.so) is available then PEM files
              may be loaded. If you want to use a file from the current directory, please precede it  with  "./"
              prefix, in order to avoid confusion with a nickname.  If the nickname contains ":", it needs to be
              preceded by "\" so that it is not recognized as password delimiter.  If the nickname contains "\",
              it needs to be escaped as "\\" so that it is not recognized as an escape character.

              (iOS  and  macOS  only) If curl is built against Secure Transport, then the certificate string can
              either be the name of a certificate/private key in the system or user keychain, or the path  to  a
              PKCS#12-encoded certificate and private key. If you want to use a file from the current directory,
              please precede it with "./" prefix, in order to avoid confusion with a nickname.

              If this option is used several times, the last one will be used.

              See also --cert-type and --key and --key-type.

       --ciphers <list of ciphers>
              (TLS)  Specifies  which  ciphers  to use in the connection. The list of ciphers must specify valid
              ciphers. Read up on SSL cipher list details on this URL:

               https://curl.haxx.se/docs/ssl-ciphers.html

              If this option is used several times, the last one will be used.

       --compressed-ssh
              (SCP SFTP) Enables built-in SSH compression.  This is a request, not an order; the server  may  or
              may not do it.

              Added in 7.56.0.

       --compressed
              (HTTP)  Request  a  compressed  response  using  one of the algorithms curl supports, and save the
              uncompressed document.  If this option is used and the server sends an unsupported encoding,  curl
              will report an error.

       -K, --config <file>

              Specify a text file to read curl arguments from. The command line arguments found in the text file
              will be used as if they were provided on the command line.

              Options  and  their  parameters  must  be  specified  on  the  same line in the file, separated by
              whitespace, colon, or the equals sign. Long option names can optionally be  given  in  the  config
              file  without  the  initial double dashes and if so, the colon or equals characters can be used as
              separators. If the option is specified with one or two dashes, there can be  no  colon  or  equals
              character between the option and its parameter.

              If  the  parameter  is to contain whitespace, the parameter must be enclosed within quotes. Within
              double quotes, the following escape sequences are  available:  \\,  \",  \t,  \n,  \r  and  \v.  A
              backslash  preceding  any  other  letter is ignored. If the first column of a config line is a '#'
              character, the rest of the line will be treated as a comment. Only write one option  per  physical
              line in the config file.

              Specify the filename to -K, --config as '-' to make curl read the file from stdin.

              Note  that  to be able to specify a URL in the config file, you need to specify it using the --url
              option, and not by simply writing the URL on its own line. So, it could look similar to this:

              url = "https://curl.haxx.se/docs/"

              When curl is invoked, it (unless -q, --disable is used) checks for a default config file and  uses
              it if found. The default config file is checked for in the following places in this order:

              1)  curl  tries  to  find  the  "home  dir":  It  first checks for the CURL_HOME and then the HOME
              environment variables. Failing that, it uses getpwuid() on Unix-like systems  (which  returns  the
              home  dir  given  the  current  user  in  your system). On Windows, it then checks for the APPDATA
              variable, or as a last resort the '%USERPROFILE%\Application Data'.

              2) On windows, if there is no _curlrc file in the home dir, it checks for one in the same dir  the
              curl  executable  is  placed.  On  Unix-like  systems, it will simply try to load .curlrc from the
              determined home dir.

              # --- Example file ---
              # this is a comment
              url = "example.com"
              output = "curlhere.html"
              user-agent = "superagent/1.0"

              # and fetch another URL too
              url = "example.com/docs/manpage.html"
              -O
              referer = "http://nowhereatall.example.com/"
              # --- End of example file ---

              This option can be used multiple times to load multiple config files.

       --connect-timeout <seconds>
              Maximum time in seconds that you allow curl's connection to take.  This only limits the connection
              phase, so if curl connects within the given period it will continue - if not it will exit.   Since
              version 7.32.0, this option accepts decimal values.

              If this option is used several times, the last one will be used.

              See also -m, --max-time.

       --connect-to <HOST1:PORT1:HOST2:PORT2>

              For  a  request  to  the  given  HOST1:PORT1 pair, connect to HOST2:PORT2 instead.  This option is
              suitable to direct requests at a specific server, e.g. at a specific cluster node in a cluster  of
              servers.  This  option  is  only  used to establish the network connection. It does NOT affect the
              hostname/port that is used for TLS/SSL (e.g. SNI, certificate verification) or for the application
              protocols. "HOST1" and "PORT1" may be the empty  string,  meaning  "any  host/port".  "HOST2"  and
              "PORT2" may also be the empty string, meaning "use the request's original host/port".

              A  "host"  specified to this option is compared as a string, so it needs to match the name used in
              request URL. It can be either numerical such  as  "127.0.0.1"  or  the  full  host  name  such  as
              "example.org".

              This option can be used many times to add many connect rules.

              See also --resolve and -H, --header. Added in 7.49.0.

       -C, --continue-at <offset>
              Continue/Resume a previous file transfer at the given offset. The given offset is the exact number
              of  bytes  that  will  be  skipped,  counting  from  the beginning of the source file before it is
              transferred to the destination.  If used with uploads, the FTP server command  SIZE  will  not  be
              used by curl.

              Use  "-C  -" to tell curl to automatically find out where/how to resume the transfer. It then uses
              the given output/input files to figure that out.

              If this option is used several times, the last one will be used.

              See also -r, --range.

       -c, --cookie-jar <filename>
              (HTTP) Specify to which file you want curl to write all cookies after a completed operation.  Curl
              writes  all  cookies from its in-memory cookie storage to the given file at the end of operations.
              If no cookies are known, no data will be written. The file will  be  written  using  the  Netscape
              cookie file format. If you set the file name to a single dash, "-", the cookies will be written to
              stdout.

              This  command  line option will activate the cookie engine that makes curl record and use cookies.
              Another way to activate it is to use the -b, --cookie option.

              If the cookie jar can't be created or written to, the whole curl  operation  won't  fail  or  even
              report  an  error  clearly. Using -v, --verbose will get a warning displayed, but that is the only
              visible feedback you get about this possibly lethal situation.

              If this option is used several times, the last specified file name will be used.

       -b, --cookie <data>
              (HTTP) Pass the data to the HTTP server in the Cookie header. It is supposedly the data previously
              received from the server in a "Set-Cookie:" line.  The data should be in the format "NAME1=VALUE1;
              NAME2=VALUE2".

              If no '=' symbol is used in the argument, it is instead treated as a filename to  read  previously
              stored  cookie  from.  This  option  also  activates the cookie engine which will make curl record
              incoming cookies, which may be handy if you're using this in combination with the  -L,  --location
              option or do multiple URL transfers on the same invoke.

              The  file  format of the file to read cookies from should be plain HTTP headers (Set-Cookie style)
              or the Netscape/Mozilla cookie file format.

              The file specified with -b, --cookie is only used as input. No cookies  will  be  written  to  the
              file. To store cookies, use the -c, --cookie-jar option.

              Exercise  caution  if  you are using this option and multiple transfers may occur.  If you use the
              NAME1=VALUE1; format, or in a file use the Set-Cookie format and don't specify a domain, then  the
              cookie  is  sent  for  any  domain (even after redirects are followed) and cannot be modified by a
              server-set cookie. If the cookie engine is enabled and a server sets a cookie  of  the  same  name
              then  both  will  be  sent  on a future transfer to that server, likely not what you intended.  To
              address these issues set a domain in Set-Cookie (doing that will include sub domains) or  use  the
              Netscape format.

              If this option is used several times, the last one will be used.

              Users  very  often want to both read cookies from a file and write updated cookies back to a file,
              so using both -b, --cookie and -c, --cookie-jar in the same command line is common.

       --create-dirs
              When used in conjunction with the -o, --output  option,  curl  will  create  the  necessary  local
              directory  hierarchy  as  needed.  This  option  creates  the dirs mentioned with the -o, --output
              option, nothing else. If the --output file name uses no dir or if the  dirs  it  mentions  already
              exist, no dir will be created.

              To create remote directories when using FTP or SFTP, try --ftp-create-dirs.

       --crlf (FTP SMTP) Convert LF to CRLF in upload. Useful for MVS (OS/390).

              (SMTP added in 7.40.0)

       --crlfile <file>
              (TLS)  Provide  a  file  using PEM format with a Certificate Revocation List that may specify peer
              certificates that are to be considered revoked.

              If this option is used several times, the last one will be used.

              Added in 7.19.7.

       --data-ascii <data>
              (HTTP) This is just an alias for -d, --data.

       --data-binary <data>
              (HTTP) This posts data exactly as specified with no extra processing whatsoever.

              If you start the data with the letter @, the rest should be a  filename.   Data  is  posted  in  a
              similar  manner  as  -d,  --data does, except that newlines and carriage returns are preserved and
              conversions are never done.

              If this option is used several times, the ones following the first will append data  as  described
              in -d, --data.

       --data-raw <data>
              (HTTP)  This  posts  data  similarly to -d, --data but without the special interpretation of the @
              character.

              See also -d, --data. Added in 7.43.0.

       --data-urlencode <data>
              (HTTP) This posts data, similar to the other -d, --data  options  with  the  exception  that  this
              performs URL-encoding.

              To  be  CGI-compliant,  the  <data>  part  should  begin with a name followed by a separator and a
              content specification. The <data> part can be passed to curl using one of the following syntaxes:

              content
                     This will make curl URL-encode the content and pass that on. Just be careful  so  that  the
                     content  doesn't contain any = or @ symbols, as that will then make the syntax match one of
                     the other cases below!

              =content
                     This will make curl URL-encode the content and pass that on. The preceding = symbol is  not
                     included in the data.

              name=content
                     This  will  make curl URL-encode the content part and pass that on. Note that the name part
                     is expected to be URL-encoded already.

              @filename
                     This will make curl load data from the given file (including any newlines), URL-encode that
                     data and pass it on in the POST.

              name@filename
                     This will make curl load data from the given file (including any newlines), URL-encode that
                     data and pass it on in the POST. The name part gets an equal sign  appended,  resulting  in
                     name=urlencoded-file-content. Note that the name is expected to be URL-encoded already.

       See also -d, --data and --data-raw. Added in 7.18.0.

       -d, --data <data>
              (HTTP)  Sends  the  specified  data  in  a POST request to the HTTP server, in the same way that a
              browser does when a user has filled in an HTML form and presses the submit button. This will cause
              curl to pass the data to the  server  using  the  content-type  application/x-www-form-urlencoded.
              Compare to -F, --form.

              --data-raw  is  almost  the same but does not have a special interpretation of the @ character. To
              post data purely binary, you should instead use the --data-binary option.  To URL-encode the value
              of a form field you may use --data-urlencode.

              If any of these options is used more than once on the same command line, the data pieces specified
              will be merged together with a separating &-symbol. Thus, using '-d  name=daniel  -d  skill=lousy'
              would generate a post chunk that looks like 'name=daniel&skill=lousy'.

              If  you start the data with the letter @, the rest should be a file name to read the data from, or
              - if you want curl to read the data from stdin. Multiple files can also be specified. Posting data
              from a file named from a file like that, carriage returns and newlines will be  stripped  out.  If
              you don't want the @ character to have a special interpretation use --data-raw instead.

              See  also  --data-binary and --data-urlencode and --data-raw. This option overrides -F, --form and
              -I, --head and --upload.

       --delegation <LEVEL>
              (GSS/kerberos) Set LEVEL to tell the server what it is allowed to delegate when it comes  to  user
              credentials.

              none   Don't allow any delegation.

              policy Delegates  if  and  only  if the OK-AS-DELEGATE flag is set in the Kerberos service ticket,
                     which is a matter of realm policy.

              always Unconditionally allow the server to delegate.

       --digest
              (HTTP) Enables HTTP Digest authentication. This is an  authentication  scheme  that  prevents  the
              password  from being sent over the wire in clear text. Use this in combination with the normal -u,
              --user option to set user name and password.

              If this option is used several times, only the first one is used.

              See also -u, --user and --proxy-digest and --anyauth. This option overrides --basic and --ntlm and
              --negotiate.

       --disable-eprt
              (FTP) Tell curl to disable the use of the EPRT and LPRT commands when doing active FTP  transfers.
              Curl  will  normally  always first attempt to use EPRT, then LPRT before using PORT, but with this
              option, it will use PORT right away. EPRT and LPRT are extensions to the  original  FTP  protocol,
              and  may  not  work  on  all  servers, but they enable more functionality in a better way than the
              traditional PORT command.

              --eprt can be used to explicitly enable EPRT again and --no-eprt is an alias for --disable-eprt.

              If the server is accessed using IPv6, this option will have no effect as EPRT is necessary then.

              Disabling EPRT only changes the active behavior. If you want to switch to passive mode you need to
              not use -P, --ftp-port or force it with --ftp-pasv.

       --disable-epsv
              (FTP) (FTP) Tell curl to disable the use of the EPSV command when  doing  passive  FTP  transfers.
              Curl will normally always first attempt to use EPSV before PASV, but with this option, it will not
              try using EPSV.

              --epsv can be used to explicitly enable EPSV again and --no-epsv is an alias for --disable-epsv.

              If the server is an IPv6 host, this option will have no effect as EPSV is necessary then.

              Disabling EPSV only changes the passive behavior. If you want to switch to active mode you need to
              use -P, --ftp-port.

       -q, --disable
              If  used  as  the first parameter on the command line, the curlrc config file will not be read and
              used. See the -K, --config for details on the default config file search path.

       --dns-interface <interface>
              (DNS) Tell curl to send outgoing DNS requests through <interface>. This option is a counterpart to
              --interface (which does not affect DNS). The supplied string must be an  interface  name  (not  an
              address).

              See also --dns-ipv4-addr and --dns-ipv6-addr. --dns-interface requires that the underlying libcurl
              was built to support c-ares. Added in 7.33.0.

       --dns-ipv4-addr <address>
              (DNS)  Tell  curl  to bind to <ip-address> when making IPv4 DNS requests, so that the DNS requests
              originate from this address. The argument should be a single IPv4 address.

              See also --dns-interface and --dns-ipv6-addr. --dns-ipv4-addr requires that the underlying libcurl
              was built to support c-ares. Added in 7.33.0.

       --dns-ipv6-addr <address>
              (DNS) Tell curl to bind to <ip-address> when making IPv6 DNS requests, so that  the  DNS  requests
              originate from this address. The argument should be a single IPv6 address.

              See also --dns-interface and --dns-ipv4-addr. --dns-ipv6-addr requires that the underlying libcurl
              was built to support c-ares. Added in 7.33.0.

       --dns-servers <addresses>
              Set  the  list  of DNS servers to be used instead of the system default.  The list of IP addresses
              should be separated with commas. Port numbers may also optionally be given as :<port-number> after
              each IP address.

              --dns-servers requires that the underlying libcurl was built to support c-ares. Added in 7.33.0.

       -D, --dump-header <filename>
              (HTTP FTP) Write the received protocol headers to the specified file.

              This option is handy to use when you want to store the headers that an HTTP  site  sends  to  you.
              Cookies  from the headers could then be read in a second curl invocation by using the -b, --cookie
              option! The -c, --cookie-jar option is a better way to store cookies.

              When used in FTP, the FTP server response lines are considered being "headers" and thus are  saved
              there.

              If this option is used several times, the last one will be used.

              See also -o, --output.

       --egd-file <file>
              (TLS) Specify the path name to the Entropy Gathering Daemon socket. The socket is used to seed the
              random engine for SSL connections.

              See also --random-file.

       --engine <name>
              (TLS)  Select the OpenSSL crypto engine to use for cipher operations. Use --engine list to print a
              list of build-time supported engines. Note that not all (or none) of the engines may be  available
              at run-time.

       --expect100-timeout <seconds>
              (HTTP)  Maximum  time in seconds that you allow curl to wait for a 100-continue response when curl
              emits an Expects: 100-continue header in its request. By default curl will wait one  second.  This
              option  accepts  decimal  values! When curl stops waiting, it will continue as if the response has
              been received.

              See also --connect-timeout. Added in 7.47.0.

       --fail-early
              Fail and exit on the first detected transfer error.

              When curl is used to do multiple transfers on the command line, it will attempt to operate on each
              given URL, one by one. By default, it will ignore errors if there are more URLs given and the last
              URL's success will determine the error code curl returns. So early failures will  be  "hidden"  by
              subsequent successful transfers.

              Using this option, curl will instead return an error on the first transfer that fails, independent
              of  the  amount  of  URLs  that  are  given on the command line. This way, no transfer failures go
              undetected by scripts and similar.

              This option is global and does not need to be specified for each use of -:, --next.

              This option does not imply -f, --fail, which causes transfers to fail due  to  the  server's  HTTP
              status  code.  You  can  combine  the  two  options,  however note -f, --fail is not global and is
              therefore contained by -:, --next.

              Added in 7.52.0.

       -f, --fail
              (HTTP) Fail silently (no output at all) on server errors. This is mostly  done  to  better  enable
              scripts  etc  to  better  deal  with failed attempts. In normal cases when an HTTP server fails to
              deliver a document, it returns an HTML document stating so (which often  also  describes  why  and
              more). This flag will prevent curl from outputting that and return error 22.

              This method is not fail-safe and there are occasions where non-successful response codes will slip
              through, especially when authentication is involved (response codes 401 and 407).

       --false-start
              (TLS)  Tells  curl  to use false start during the TLS handshake. False start is a mode where a TLS
              client will start sending application data before verifying the server's  Finished  message,  thus
              saving a round trip when performing a full handshake.

              This  is  currently only implemented in the NSS and Secure Transport (on iOS 7.0 or later, or OS X
              10.9 or later) backends.

              Added in 7.42.0.

       --form-string <name=string>
              (HTTP SMTP IMAP) Similar to -F, --form except that the value string for  the  named  parameter  is
              used  literally.  Leading  '@'  and  '<'  characters, and the ';type=' string in the value have no
              special meaning. Use this in preference to -F, --form if there's any possibility that  the  string
              value may accidentally trigger the '@' or '<' features of -F, --form.

              See also -F, --form.

       -F, --form <name=content>
              (HTTP SMTP IMAP) For HTTP protocol family, this lets curl emulate a filled-in form in which a user
              has   pressed   the  submit  button.  This  causes  curl  to  POST  data  using  the  Content-Type
              multipart/form-data according to RFC 2388.

              For SMTP and IMAP protocols, this is the mean to compose a multipart mail message to transmit.

              This enables uploading of binary files etc. To force the 'content' part to be a file,  prefix  the
              file  name with an @ sign. To just get the content part from a file, prefix the file name with the
              symbol <. The difference between @ and < is then that @ makes a file get attached in the post as a
              file upload, while the < makes a text field and just get the contents for that text field  from  a
              file.

              Example:  to  send  an  image  to an HTTP server, where 'profile' is the name of the form-field to
              which portrait.jpg will be the input:

               curl -F profile=@portrait.jpg https://example.com/upload.cgi

              To read content from stdin instead of a file, use - as the filename. This goes for both  @  and  <
              constructs. If stdin is not attached to a regular file, it is buffered first to determine its size
              and allow a possible resend. Defining a part's data from a named non-regular file (such as a named
              pipe  or  similar)  is  unfortunately  not  subject  to  buffering and will be effectively read at
              transmission time; since the full size is unknown before the transfer  starts,  data  is  sent  as
              chunks by HTTP and rejected by IMAP.

              You can also tell curl what Content-Type to use by using 'type=', in a manner similar to:

               curl -F "web=@index.html;type=text/html" example.com

              or

               curl -F "name=daniel;type=text/foo" example.com

              You  can  also  explicitly  change the name field of a file upload part by setting filename=, like
              this:

               curl -F "file=@localfile;filename=nameinpost" example.com

              If filename/path contains ',' or ';', it must be quoted by double-quotes like:

               curl -F "file=@\"localfile\";filename=\"nameinpost\"" example.com

              or

               curl -F 'file=@"localfile";filename="nameinpost"' example.com

              Note that if a filename/path is quoted by double-quotes, any double-quote or backslash within  the
              filename must be escaped by backslash.

              Quoting  must  also be applied to non-file data if it contains semicolons, leading/trailing spaces
              or leading double quotes:

               curl -F 'colors="red; green; blue";type=text/x-myapp' example.com

              You can add custom headers to the field by setting headers=, like

                curl -F "submit=OK;headers=\"X-submit-type: OK\"" example.com

              or

                curl -F "submit=OK;headers=@headerfile" example.com

              The headers= keyword may appear more that once and above notes about quoting apply.  When  headers
              are  read  from  a  file,  Empty  lines and lines starting with '#' are comments and ignored; each
              header can be folded by splitting between two words and starting  the  continuation  line  with  a
              space; embedded carriage-returns and trailing spaces are stripped.  Here is an example of a header
              file contents:

                # This file contain two headers.
                X-header-1: this is a header

                # The following header is folded.
                X-header-2: this is
                 another header

              To support sending multipart mail messages, the syntax is extended as follows:
              - name can be omitted: the equal sign is the first character of the argument,
              -  if data starts with '(', this signals to start a new multipart: it can be followed by a content
              type specification.
              - a multipart can be terminated with a '=)' argument.

              Example: the following command sends an SMTP mime e-mail consisting  in  an  inline  part  in  two
              alternative formats: plain text and HTML. It attaches a text file:

               curl -F '=(;type=multipart/alternative' \
                       -F '=plain text message' \
                       -F '= <body>HTML message</body>;type=text/html' \
                    -F '=)' -F '=@textfile.txt' ...  smtp://example.com

              Data  can  be encoded for transfer using encoder=. Available encodings are binary and 8bit that do
              nothing else than adding  the  corresponding  Content-Transfer-Encoding  header,  7bit  that  only
              rejects  8-bit  characters  with  a  transfer error, quoted-printable and base64 that encodes data
              according to the corresponding schemes, limiting lines length to 76 characters.

              Example: send multipart mail with a quoted-printable text message and a base64 attached file:

               curl -F '=text message;encoder=quoted-printable' \
                    -F '=@localfile;encoder=base64' ... smtp://example.com

              See further examples and details in the MANUAL.

              This option can be used multiple times.

              This option overrides -d, --data and -I, --head and --upload.

       --ftp-account <data>
              (FTP) When an FTP server asks for "account data" after user name and password has  been  provided,
              this data is sent off using the ACCT command.

              If this option is used several times, the last one will be used.

              Added in 7.13.0.

       --ftp-alternative-to-user <command>
              (FTP) If authenticating with the USER and PASS commands fails, send this command.  When connecting
              to  Tumbleweed's  Secure  Transport server over FTPS using a client certificate, using "SITE AUTH"
              will tell the server to retrieve the username from the certificate.

              Added in 7.15.5.

       --ftp-create-dirs
              (FTP SFTP) When an FTP or SFTP URL/operation uses a path  that  doesn't  currently  exist  on  the
              server,  the standard behavior of curl is to fail. Using this option, curl will instead attempt to
              create missing directories.

              See also --create-dirs.

       --ftp-method <method>
              (FTP) Control what method curl should use to reach a file on an FTP(S) server. The method argument
              should be one of the following alternatives:

              multicwd
                     curl does a single CWD operation for each path part in the given URL. For deep  hierarchies
                     this  means  very  many  commands. This is how RFC 1738 says it should be done. This is the
                     default but the slowest behavior.

              nocwd  curl does no CWD at all. curl will do SIZE, RETR, STOR etc and give  a  full  path  to  the
                     server for all these commands. This is the fastest behavior.

              singlecwd
                     curl  does  one CWD with the full target directory and then operates on the file "normally"
                     (like in the multicwd case). This is somewhat more standards  compliant  than  'nocwd'  but
                     without the full penalty of 'multicwd'.

       Added in 7.15.1.

       --ftp-pasv
              (FTP)  Use  passive  mode  for  the data connection. Passive is the internal default behavior, but
              using this option can be used to override a previous -P, --ftp-port option.

              If this option is used several times, only the first one is  used.  Undoing  an  enforced  passive
              really isn't doable but you must then instead enforce the correct -P, --ftp-port again.

              Passive  mode means that curl will try the EPSV command first and then PASV, unless --disable-epsv
              is used.

              See also --disable-epsv. Added in 7.11.0.

       -P, --ftp-port <address>
              (FTP) Reverses the default initiator/listener roles when connecting with FTP.  This  option  makes
              curl use active mode. curl then tells the server to connect back to the client's specified address
              and port, while passive mode asks the server to setup an IP address and port for it to connect to.
              <address> should be one of:

              interface
                     i.e "eth0" to specify which interface's IP address you want to use (Unix only)

              IP address
                     i.e "192.168.10.1" to specify the exact IP address

              host name
                     i.e "my.host.domain" to specify the machine

              -      make curl pick the same IP address that is already used for the control connection

       If this option is used several times, the last one will be used. Disable the use of PORT with --ftp-pasv.
       Disable  the  attempt  to  use  the  EPRT command instead of PORT by using --disable-eprt. EPRT is really
       PORT++.

       Since 7.19.5, you can append ":[start]-[end]" to the right of the address, to tell  curl  what  TCP  port
       range to use. That means you specify a port range, from a lower to a higher number. A single number works
       as well, but do note that it increases the risk of failure since the port may not be available.

       See also --ftp-pasv and --disable-eprt.

       --ftp-pret
              (FTP) Tell curl to send a PRET command before PASV (and EPSV). Certain FTP servers, mainly drftpd,
              require this non-standard command for directory listings as well as up and downloads in PASV mode.

              Added in 7.20.0.

       --ftp-skip-pasv-ip
              (FTP)  Tell  curl  to  not  use  the IP address the server suggests in its response to curl's PASV
              command when curl connects the data connection. Instead curl will re-use the same  IP  address  it
              already uses for the control connection.

              This option has no effect if PORT, EPRT or EPSV is used instead of PASV.

              See also --ftp-pasv. Added in 7.14.2.

       --ftp-ssl-ccc-mode <active/passive>
              (FTP) Sets the CCC mode. The passive mode will not initiate the shutdown, but instead wait for the
              server to do it, and will not reply to the shutdown from the server. The active mode initiates the
              shutdown and waits for a reply from the server.

              See also --ftp-ssl-ccc. Added in 7.16.2.

       --ftp-ssl-ccc
              (FTP)  Use CCC (Clear Command Channel) Shuts down the SSL/TLS layer after authenticating. The rest
              of the control channel communication will be unencrypted. This allows NAT routers  to  follow  the
              FTP transaction. The default mode is passive.

              See also --ssl and --ftp-ssl-ccc-mode. Added in 7.16.1.

       --ftp-ssl-control
              (FTP)  Require  SSL/TLS  for the FTP login, clear for transfer.  Allows secure authentication, but
              non-encrypted data transfers for efficiency.  Fails the transfer if  the  server  doesn't  support
              SSL/TLS.

              Added in 7.16.0.

       -G, --get
              When  used,  this  option  will  make all data specified with -d, --data, --data-binary or --data-
              urlencode to be used in an HTTP GET request instead of the POST request that  otherwise  would  be
              used. The data will be appended to the URL with a '?' separator.

              If  used  in combination with -I, --head, the POST data will instead be appended to the URL with a
              HEAD request.

              If this option is used several times, only the first one is used. This is because  undoing  a  GET
              doesn't make sense, but you should then instead enforce the alternative method you prefer.

       -g, --globoff
              This option switches off the "URL globbing parser". When you set this option, you can specify URLs
              that  contain  the  letters  {}[]  without having them being interpreted by curl itself. Note that
              these letters are not normal legal URL contents but they should be encoded according  to  the  URI
              standard.

       -I, --head
              (HTTP  FTP  FILE) Fetch the headers only! HTTP-servers feature the command HEAD which this uses to
              get nothing but the header of a document. When used on an FTP or FILE file, curl displays the file
              size and last modification time only.

       -H, --header <header/@file>
              (HTTP) Extra header to include in the request when sending HTTP to a server. You may  specify  any
              number of extra headers. Note that if you should add a custom header that has the same name as one
              of  the  internal  ones  curl  would  use,  your externally set header will be used instead of the
              internal one. This allows you to make even trickier stuff than curl would normally do. You  should
              not  replace  internally  set  headers without knowing perfectly well what you're doing. Remove an
              internal header by giving a replacement without content on the right side of the colon, as in:  -H
              "Host:".  If  you  send  the custom header with no-value then its header must be terminated with a
              semicolon, such as -H "X-Custom-Header;" to send "X-Custom-Header:".

              curl will make sure that each header you add/replace is sent with the proper  end-of-line  marker,
              you  should  thus  not  add  that as a part of the header content: do not add newlines or carriage
              returns, they will only mess things up for you.

              Starting in 7.55.0, this option can take an argument in @filename style, which then adds a  header
              for each line in the input file. Using @- will make curl read the header file from stdin.

              See also the -A, --user-agent and -e, --referer options.

              Starting in 7.37.0, you need --proxy-header to send custom headers intended for a proxy.

              Example:

               curl -H "X-First-Name: Joe" http://example.com/

              WARNING:  headers  set  with  this  option  will be set in all requests - even after redirects are
              followed, like when told with -L, --location. This can lead to the  header  being  sent  to  other
              hosts  than  the  original  host,  so  sensitive headers should be used with caution combined with
              following redirects.

              This option can be used multiple times to add/replace/remove multiple headers.

       -h, --help
              Usage help. This lists all current command line options with a short description.

       --hostpubmd5 <md5>
              (SFTP SCP) Pass a string containing 32 hexadecimal digits. The string should be the  128  bit  MD5
              checksum of the remote host's public key, curl will refuse the connection with the host unless the
              md5sums match.

              Added in 7.17.1.

       -0, --http1.0
              (HTTP) Tells curl to use HTTP version 1.0 instead of using its internally preferred HTTP version.

              This option overrides --http1.1 and --http2.

       --http1.1
              (HTTP) Tells curl to use HTTP version 1.1.

              This option overrides -0, --http1.0 and --http2. Added in 7.33.0.

       --http2-prior-knowledge
              (HTTP)  Tells  curl  to  issue its non-TLS HTTP requests using HTTP/2 without HTTP/1.1 Upgrade. It
              requires prior knowledge that the server supports HTTP/2 straight away. HTTPS requests will  still
              do HTTP/2 the standard way with negotiated protocol version in the TLS handshake.

              --http2-prior-knowledge  requires  that  the  underlying libcurl was built to support HTTP/2. This
              option overrides --http1.1 and -0, --http1.0 and --http2. Added in 7.49.0.

       --http2
              (HTTP) Tells curl to use HTTP version 2.

              See also --no-alpn. --http2 requires that the underlying libcurl was built to support HTTP/2. This
              option overrides --http1.1 and -0, --http1.0 and --http2-prior-knowledge. Added in 7.33.0.

       --ignore-content-length
              (FTP HTTP) For HTTP, Ignore the Content-Length header. This is  particularly  useful  for  servers
              running Apache 1.x, which will report incorrect Content-Length for files larger than 2 gigabytes.

              For FTP (since 7.46.0), skip the RETR command to figure out the size before downloading a file.

       -i, --include
              Include the HTTP response headers in the output. The HTTP response headers can include things like
              server name, cookies, date of the document, HTTP version and more...

              To view the request headers, consider the -v, --verbose option.

              See also -v, --verbose.

       -k, --insecure
              (TLS)  By  default,  every  SSL connection curl makes is verified to be secure. This option allows
              curl to proceed and operate even for server connections otherwise considered insecure.

              The server connection is verified by making sure the server's certificate contains the right  name
              and verifies successfully using the cert store.

              See this online resource for further details:
               https://curl.haxx.se/docs/sslcerts.html

              See also --proxy-insecure and --cacert.

       --interface <name>

              Perform an operation using a specified interface. You can enter interface name, IP address or host
              name. An example could look like:

               curl --interface eth0:1 https://www.example.com/

              If this option is used several times, the last one will be used.

              On Linux it can be used to specify a VRF, but the binary needs to either have CAP_NET_RAW or to be
              ran         as         root.         More        information        about        Linux        VRF:
              https://www.kernel.org/doc/Documentation/networking/vrf.txt

              See also --dns-interface.

       -4, --ipv4
              This option tells curl to resolve names to IPv4 addresses only, and not for example try IPv6.

              See also --http1.1 and --http2. This option overrides -6, --ipv6.

       -6, --ipv6
              This option tells curl to resolve names to IPv6 addresses only, and not for example try IPv4.

              See also --http1.1 and --http2. This option overrides -6, --ipv6.

       -j, --junk-session-cookies
              (HTTP) When curl is told to read cookies from a given file, this option will make it  discard  all
              "session  cookies".  This  will  basically  have  the  same effect as if a new session is started.
              Typical browsers always discard session cookies when they're closed down.

              See also -b, --cookie and -c, --cookie-jar.

       --keepalive-time <seconds>
              This option sets the time a connection needs to remain idle before sending  keepalive  probes  and
              the  time  between  individual  keepalive  probes.  It is currently effective on operating systems
              offering the TCP_KEEPIDLE and TCP_KEEPINTVL socket options (meaning Linux, recent AIX,  HP-UX  and
              more). This option has no effect if --no-keepalive is used.

              If  this  option  is  used  several  times,  the last one will be used. If unspecified, the option
              defaults to 60 seconds.

              Added in 7.18.0.

       --key-type <type>
              (TLS) Private key file type. Specify which type your --key provided private key is. DER, PEM,  and
              ENG are supported. If not specified, PEM is assumed.

              If this option is used several times, the last one will be used.

       --key <key>
              (TLS SSH) Private key file name. Allows you to provide your private key in this separate file. For
              SSH, if not specified, curl tries the following candidates in order:

              If this option is used several times, the last one will be used.

       --krb <level>
              (FTP)  Enable  Kerberos  authentication  and  use.  The level must be entered and should be one of
              'clear', 'safe', 'confidential', or 'private'. Should you use a level that is not  one  of  these,
              'private' will instead be used.

              If this option is used several times, the last one will be used.

              --krb requires that the underlying libcurl was built to support Kerberos.

       --libcurl <file>
              Append  this  option  to any ordinary curl command line, and you will get a libcurl-using C source
              code written to the file that does the equivalent of what your command-line operation does!

              If this option is used several times, the last given file name will be used.

              Added in 7.16.1.

       --limit-rate <speed>
              Specify the maximum transfer rate you want curl to use - for  both  downloads  and  uploads.  This
              feature  is  useful if you have a limited pipe and you'd like your transfer not to use your entire
              bandwidth. To make it slower than it otherwise would be.

              The given speed is measured in bytes/second, unless a suffix is appended.  Appending  'k'  or  'K'
              will  count  the  number  as  kilobytes,  'm' or 'M' makes it megabytes, while 'g' or 'G' makes it
              gigabytes. Examples: 200K, 3m and 1G.

              If you also use the -Y, --speed-limit option, that option will take precedence and  might  cripple
              the rate-limiting slightly, to help keeping the speed-limit logic working.

              If this option is used several times, the last one will be used.

       -l, --list-only
              (FTP  POP3)  (FTP)  When  listing  an  FTP directory, this switch forces a name-only view. This is
              especially useful if the user wants to machine-parse the contents of an FTP  directory  since  the
              normal  directory  view  doesn't  use  a  standard look or format. When used like this, the option
              causes a NLST command to be sent to the server instead of LIST.

              Note: Some FTP servers list only files in their  response  to  NLST;  they  do  not  include  sub-
              directories and symbolic links.

              (POP3)  When  retrieving  a  specific  email  from  POP3,  this switch forces a LIST command to be
              performed instead of RETR. This is particularly useful if the user wants  to  see  if  a  specific
              message id exists on the server and what size it is.

              Note:  When  combined with -X, --request, this option can be used to send an UIDL command instead,
              so the user may use the email's unique identifier rather than it's message id to make the request.

              Added in 7.21.5.

       --local-port <num/range>
              Set a preferred  single  number  or  range  (FROM-TO)  of  local  port  numbers  to  use  for  the
              connection(s).   Note that port numbers by nature are a scarce resource that will be busy at times
              so setting this range to something too narrow might cause unnecessary connection setup failures.

              Added in 7.15.2.

       --location-trusted
              (HTTP) Like -L, --location, but will allow sending the name + password to all hosts that the  site
              may  redirect  to.  This may or may not introduce a security breach if the site redirects you to a
              site to which you'll send your authentication info (which is plaintext in the case of  HTTP  Basic
              authentication).

              See also -u, --user.

       -L, --location
              (HTTP)  If the server reports that the requested page has moved to a different location (indicated
              with a Location: header and a 3XX response code), this option will make curl redo the  request  on
              the new place. If used together with -i, --include or -I, --head, headers from all requested pages
              will  be  shown. When authentication is used, curl only sends its credentials to the initial host.
              If a redirect takes curl to a different host, it won't be able to intercept the user+password. See
              also --location-trusted on how to change this. You can limit the amount of redirects to follow  by
              using the --max-redirs option.

              When curl follows a redirect and the request is not a plain GET (for example POST or PUT), it will
              do  the  following  request  with a GET if the HTTP response was 301, 302, or 303. If the response
              code was any other 3xx code, curl will re-send the following request  using  the  same  unmodified
              method.

              You  can  tell  curl to not change the non-GET request method to GET after a 30x response by using
              the dedicated options for that: --post301, --post302 and --post303.

       --login-options <options>
              (IMAP POP3 SMTP) Specify the login options to use during server authentication.

              You can use the login options to specify  protocol  specific  options  that  may  be  used  during
              authentication.  At  present  only IMAP, POP3 and SMTP support login options. For more information
              about the login options please see RFC 2384, RFC 5092 and IETF draft draft-earhart-url-smtp-00.txt

              If this option is used several times, the last one will be used.

              Added in 7.34.0.

       --mail-auth <address>
              (SMTP) Specify a single  address.  This  will  be  used  to  specify  the  authentication  address
              (identity) of a submitted message that is being relayed to another server.

              See also --mail-rcpt and --mail-from. Added in 7.25.0.

       --mail-from <address>
              (SMTP) Specify a single address that the given mail should get sent from.

              See also --mail-rcpt and --mail-auth. Added in 7.20.0.

       --mail-rcpt <address>
              (SMTP)  Specify a single address, user name or mailing list name. Repeat this option several times
              to send to multiple recipients.

              When performing a mail transfer, the recipient should specify a valid email address  to  send  the
              mail to.

              When  performing  an address verification (VRFY command), the recipient should be specified as the
              user name or user name and domain (as per Section 3.5 of RFC5321). (Added in 7.34.0)

              When performing a mailing list expand (EXPN command), the recipient should be specified using  the
              mailing list name, such as "Friends" or "London-Office".  (Added in 7.34.0)

              Added in 7.20.0.

       -M, --manual
              Manual. Display the huge help text.

       --max-filesize <bytes>
              Specify  the  maximum  size (in bytes) of a file to download. If the file requested is larger than
              this value, the transfer will not start and curl will return with exit code 63.

              A size modifier may be used. For example, Appending 'k' or 'K' will count the number as kilobytes,
              'm' or 'M' makes it megabytes, while 'g' or 'G' makes it gigabytes. Examples:  200K,  3m  and  1G.
              (Added in 7.58.0)

              NOTE:  The  file size is not always known prior to download, and for such files this option has no
              effect even if the file transfer ends up being larger than this given limit.  This  concerns  both
              FTP and HTTP transfers.

              See also --limit-rate.

       --max-redirs <num>
              (HTTP)  Set maximum number of redirection-followings allowed. When -L, --location is used, is used
              to prevent curl from following redirections "in absurdum". By default, the  limit  is  set  to  50
              redirections. Set this option to -1 to make it unlimited.

              If this option is used several times, the last one will be used.

       -m, --max-time <time>
              Maximum time in seconds that you allow the whole operation to take.  This is useful for preventing
              your  batch  jobs  from hanging for hours due to slow networks or links going down.  Since 7.32.0,
              this option accepts decimal values, but the actual  timeout  will  decrease  in  accuracy  as  the
              specified timeout increases in decimal precision.

              If this option is used several times, the last one will be used.

              See also --connect-timeout.

       --metalink
              This  option can tell curl to parse and process a given URI as Metalink file (both version 3 and 4
              (RFC 5854) are supported) and make use of the mirrors listed within  for  failover  if  there  are
              errors  (such as the file or server not being available). It will also verify the hash of the file
              after the download completes. The Metalink file itself is downloaded and processed in  memory  and
              not stored in the local file system.

              Example to use a remote Metalink file:

               curl --metalink http://www.example.com/example.metalink

              To use a Metalink file in the local file system, use FILE protocol (file://):

               curl --metalink file://example.metalink

              Please note that if FILE protocol is disabled, there is no way to use a local Metalink file at the
              time  of this writing. Also note that if --metalink and -i, --include are used together, --include
              will be ignored. This is because including headers in the response will break Metalink parser  and
              if the headers are included in the file described in Metalink file, hash check will fail.

              --metalink requires that the underlying libcurl was built to support metalink. Added in 7.27.0.

       --negotiate
              (HTTP) Enables Negotiate (SPNEGO) authentication.

              This  option  requires  a  library built with GSS-API or SSPI support. Use -V, --version to see if
              your curl supports GSS-API/SSPI or SPNEGO.

              When using this option,  you  must  also  provide  a  fake  -u,  --user  option  to  activate  the
              authentication  code  properly.  Sending a '-u :' is enough as the user name and password from the
              -u, --user option aren't actually used.

              If this option is used several times, only the first one is used.

              See also --basic and --ntlm and --anyauth and --proxy-negotiate.

       --netrc-file <filename>
              This option is similar to -n, --netrc, except that you provide the path (absolute or relative)  to
              the  netrc  file  that  Curl  should  use.  You can only specify one netrc file per invocation. If
              several --netrc-file options are provided, the last one will be used.

              It will abide by --netrc-optional if specified.

              This option overrides -n, --netrc. Added in 7.21.5.

       --netrc-optional
              Very similar to -n, --netrc, but this option makes the .netrc usage optional and not mandatory  as
              the -n, --netrc option does.

              See also --netrc-file. This option overrides -n, --netrc.

       -n, --netrc
              Makes  curl  scan  the .netrc (_netrc on Windows) file in the user's home directory for login name
              and password. This is typically used for FTP on Unix. If used with HTTP,  curl  will  enable  user
              authentication. See netrc(5) ftp(1) for details on the file format. Curl will not complain if that
              file  doesn't  have  the right permissions (it should not be either world- or group-readable). The
              environment variable "HOME" is used to find the home directory.

              A quick and very simple example of how to setup a .netrc to allow  curl  to  FTP  to  the  machine
              host.domain.com with user name 'myself' and password 'secret' should look similar to:

              machine host.domain.com login myself password secret

       -:, --next
              Tells  curl  to use a separate operation for the following URL and associated options. This allows
              you to send several URL requests, each with their own  specific  options,  for  example,  such  as
              different user names or custom requests for each.

              -:,  --next  will reset all local options and only global ones will have their values survive over
              to the operation following the -:, --next  instruction.  Global  options  include  -v,  --verbose,
              --trace, --trace-ascii and --fail-early.

              For example, you can do both a GET and a POST in a single command line:

               curl www1.example.com --next -d postthis www2.example.com

              Added in 7.36.0.

       --no-alpn
              (HTTPS)  Disable  the  ALPN TLS extension. ALPN is enabled by default if libcurl was built with an
              SSL library that supports ALPN. ALPN is used by a libcurl that supports HTTP/2 to negotiate HTTP/2
              support with the server during https sessions.

              See also --no-npn and --http2. --no-alpn requires that the underlying libcurl was built to support
              TLS. Added in 7.36.0.

       -N, --no-buffer
              Disables the buffering of the output stream. In normal work situations, curl will use  a  standard
              buffered  output  stream  that  will  have  the effect that it will output the data in chunks, not
              necessarily exactly when the data arrives.  Using this option will disable that buffering.

              Note that this is the negated option name documented. You can thus use  --buffer  to  enforce  the
              buffering.

       --no-keepalive
              Disables  the  use  of  keepalive  messages  on the TCP connection. curl otherwise enables them by
              default.

              Note that this is the negated option name documented. You can  thus  use  --keepalive  to  enforce
              keepalive.

       --no-npn
              (HTTPS)  Disable the NPN TLS extension. NPN is enabled by default if libcurl was built with an SSL
              library that supports NPN. NPN is used by a libcurl  that  supports  HTTP/2  to  negotiate  HTTP/2
              support with the server during https sessions.

              See also --no-alpn and --http2. --no-npn requires that the underlying libcurl was built to support
              TLS. Added in 7.36.0.

       --no-sessionid
              (TLS)  Disable  curl's use of SSL session-ID caching.  By default all transfers are done using the
              cache. Note that while nothing should ever get hurt by attempting to reuse SSL session-IDs,  there
              seem  to  be  broken SSL implementations in the wild that may require you to disable this in order
              for you to succeed.

              Note that this is the negated option name documented. You can  thus  use  --sessionid  to  enforce
              session-ID caching.

              Added in 7.16.0.

       --noproxy <no-proxy-list>
              Comma-separated list of hosts which do not use a proxy, if one is specified.  The only wildcard is
              a  single  *  character, which matches all hosts, and effectively disables the proxy. Each name in
              this list is matched as either a domain which contains the hostname, or the hostname  itself.  For
              example,   local.com   would   match   local.com,   local.com:80,   and   www.local.com,  but  not
              www.notlocal.com.

              Since 7.53.0, This option overrides the environment variables that disable the proxy.  If  there's
              an environment variable disabling a proxy, you can set noproxy list to "" to override it.

              Added in 7.19.4.

       --ntlm-wb
              (HTTP)  Enables  NTLM  much  in  the  style  --ntlm  does, but hand over the authentication to the
              separate binary ntlmauth application that is executed when needed.

              See also --ntlm and --proxy-ntlm.

       --ntlm (HTTP) Enables NTLM authentication. The NTLM authentication method was designed by  Microsoft  and
              is  used by IIS web servers. It is a proprietary protocol, reverse-engineered by clever people and
              implemented in curl based on their efforts. This kind of behavior  should  not  be  endorsed,  you
              should encourage everyone who uses NTLM to switch to a public and documented authentication method
              instead, such as Digest.

              If you want to enable NTLM for your proxy authentication, then use --proxy-ntlm.

              If this option is used several times, only the first one is used.

              See  also --proxy-ntlm. --ntlm requires that the underlying libcurl was built to support TLS. This
              option overrides --basic and --negotiated and --digest and --anyauth.

       --oauth2-bearer <token>
              (IMAP POP3 SMTP) Specify the Bearer Token for OAUTH 2.0 server authentication. The Bearer Token is
              used in conjunction with the user name which can be specified as part of the --url or  -u,  --user
              options.

              The Bearer Token and user name are formatted according to RFC 6750.

              If this option is used several times, the last one will be used.

       -o, --output <file>
              Write  output  to <file> instead of stdout. If you are using {} or [] to fetch multiple documents,
              you can use '#' followed by a number in the <file> specifier. That variable will be replaced  with
              the current string for the URL being fetched. Like in:

               curl http://{one,two}.example.com -o "file_#1.txt"

              or use several variables like:

               curl http://{site,host}.host[1-5].com -o "#1_#2"

              You  may use this option as many times as the number of URLs you have. For example, if you specify
              two URLs on the same command line, you can use it like this:

                curl -o aa example.com -o bb example.net

              and the order of the -o options and the URLs doesn't matter, just that the first  -o  is  for  the
              first URL and so on, so the above command line can also be written as

                curl example.com example.net -o aa -o bb

              See  also  the  --create-dirs  option  to create the local directories dynamically. Specifying the
              output as '-' (a single dash) will force the output to be done to stdout.

              See also -O, --remote-name and --remote-name-all and -J, --remote-header-name.

       --pass <phrase>
              (SSH TLS) Passphrase for the private key

              If this option is used several times, the last one will be used.

       --path-as-is
              Tell curl to not handle sequences of /../ or /./ in the given URL path. Normally curl will  squash
              or merge them according to standards but with this option set you tell it not to do that.

              Added in 7.42.0.

       --pinnedpubkey <hashes>
              (TLS)  Tells curl to use the specified public key file (or hashes) to verify the peer. This can be
              a path to a file which contains a single public key in PEM or DER format, or any number of  base64
              encoded sha256 hashes preceded by ´sha256//´ and separated by ´;´

              When  negotiating a TLS or SSL connection, the server sends a certificate indicating its identity.
              A public key is extracted from this certificate and if it does not exactly match  the  public  key
              provided to this option, curl will abort the connection before sending or receiving any data.

              PEM/DER support:
                7.39.0: OpenSSL, GnuTLS and GSKit
                7.43.0: NSS and wolfSSL/CyaSSL
                7.47.0: mbedtls
                7.49.0: PolarSSL sha256 support:
                7.44.0: OpenSSL, GnuTLS, NSS and wolfSSL/CyaSSL.
                7.47.0: mbedtls
                7.49.0: PolarSSL Other SSL backends not supported.

              If this option is used several times, the last one will be used.

       --post301
              (HTTP)  Tells  curl to respect RFC 7231/6.4.2 and not convert POST requests into GET requests when
              following a 301 redirection. The non-RFC behaviour is ubiquitous in web browsers, so curl does the
              conversion by default to maintain consistency. However, a server may require a POST  to  remain  a
              POST after such a redirection. This option is meaningful only when using -L, --location.

              See also --post302 and --post303 and -L, --location. Added in 7.17.1.

       --post302
              (HTTP)  Tells  curl to respect RFC 7231/6.4.3 and not convert POST requests into GET requests when
              following a 302 redirection. The non-RFC behaviour is ubiquitous in web browsers, so curl does the
              conversion by default to maintain consistency. However, a server may require a POST  to  remain  a
              POST after such a redirection. This option is meaningful only when using -L, --location.

              See also --post301 and --post303 and -L, --location. Added in 7.19.1.

       --post303
              (HTTP)  Tells  curl to respect RFC 7231/6.4.4 and not convert POST requests into GET requests when
              following a 303 redirection. The non-RFC behaviour is ubiquitous in web browsers, so curl does the
              conversion by default to maintain consistency. However, a server may require a POST  to  remain  a
              POST after such a redirection. This option is meaningful only when using -L, --location.

              See also --post302 and --post301 and -L, --location. Added in 7.26.0.

       --preproxy [protocol://]host[:port]
              Use  the  specified  SOCKS proxy before connecting to an HTTP or HTTPS -x, --proxy. In such a case
              curl first connects to the SOCKS proxy and then connects (through SOCKS)  to  the  HTTP  or  HTTPS
              proxy. Hence pre proxy.

              The  pre  proxy  string should be specified with a protocol:// prefix to specify alternative proxy
              protocols. Use socks4://, socks4a://, socks5://  or  socks5h://  to  request  the  specific  SOCKS
              version to be used. No protocol specified will make curl default to SOCKS4.

              If the port number is not specified in the proxy string, it is assumed to be 1080.

              User  and password that might be provided in the proxy string are URL decoded by curl. This allows
              you to pass in special characters such as @ by using %40 or pass in a colon with %3a.

              If this option is used several times, the last one will be used.

              Added in 7.52.0.

       -#, --progress-bar
              Make curl display transfer progress as a  simple  progress  bar  instead  of  the  standard,  more
              informational, meter.

              This  progress  bar draws a single line of '#' characters across the screen and shows a percentage
              if the transfer size is known. For transfers without a known size, it will instead output one  '#'
              character for every 1024 bytes transferred.

       --proto-default <protocol>
              Tells curl to use protocol for any URL missing a scheme name.

              Example:

               curl --proto-default https ftp.mozilla.org

              An unknown or unsupported protocol causes error CURLE_UNSUPPORTED_PROTOCOL (1).

              This option does not change the default proxy protocol (http).

              Without this option curl would make a guess based on the host, see --url for details.

              Added in 7.45.0.

       --proto-redir <protocols>
              Tells  curl  to  limit  what protocols it may use on redirect. Protocols denied by --proto are not
              overridden by this option. See --proto for how protocols are represented.

              Example, allow only HTTP and HTTPS on redirect:

               curl --proto-redir -all,http,https http://example.com

              By default curl will allow all protocols on redirect except several disabled for security reasons:
              Since 7.19.4 FILE and SCP are  disabled,  and  since  7.40.0  SMB  and  SMBS  are  also  disabled.
              Specifying all or +all enables all protocols on redirect, including those disabled for security.

              Added in 7.20.2.

       --proto <protocols>
              Tells  curl  to  limit  what protocols it may use in the transfer. Protocols are evaluated left to
              right, are comma separated, and are each a protocol name or

              +  Permit this protocol in addition to protocols already permitted (this  is  the  default  if  no
                 modifier is used).

              -  Deny this protocol, removing it from the list of protocols already permitted.

              =  Permit  only  this  protocol  (ignoring  the  list  already permitted), though subject to later
                 modification by subsequent entries in the comma separated list.

              For example:

              --proto -ftps  uses the default protocols, but disables ftps

              --proto -all,https,+http
                             only enables http and https

              --proto =http,https
                             also only enables http and https

       Unknown protocols produce a warning. This allows  scripts  to  safely  rely  on  being  able  to  disable
       potentially  dangerous protocols, without relying upon support for that protocol being built into curl to
       avoid an error.

       This option can be used multiple times, in which case  the  effect  is  the  same  as  concatenating  the
       protocols into one instance of the option.

       See also --proto-redir and --proto-default. Added in 7.20.2.

       --proxy-anyauth
              Tells  curl to pick a suitable authentication method when communicating with the given HTTP proxy.
              This might cause an extra request/response round-trip.

              See also -x, --proxy and --proxy-basic and --proxy-digest. Added in 7.13.2.

       --proxy-basic
              Tells curl to use HTTP Basic authentication when communicating with the given proxy.  Use  --basic
              for  enabling  HTTP Basic with a remote host. Basic is the default authentication method curl uses
              with proxies.

              See also -x, --proxy and --proxy-anyauth and --proxy-digest.

       --proxy-cacert <file>
              Same as --cacert but used in HTTPS proxy context.

              See also --proxy-capath and --cacert and --capath and -x, --proxy. Added in 7.52.0.

       --proxy-capath <dir>
              Same as --capath but used in HTTPS proxy context.

              See also --proxy-cacert and -x, --proxy and --capath. Added in 7.52.0.

       --proxy-cert-type <type>
              Same as --cert-type but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-cert <cert[:passwd]>
              Same as -E, --cert but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-ciphers <list>
              Same as --ciphers but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-crlfile <file>
              Same as --crlfile but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-digest
              Tells curl to use HTTP Digest authentication when communicating with the given proxy. Use --digest
              for enabling HTTP Digest with a remote host.

              See also -x, --proxy and --proxy-anyauth and --proxy-basic.

       --proxy-header <header/@file>
              (HTTP) Extra header to include in the request when sending HTTP to a proxy. You  may  specify  any
              number  of  extra  headers.  This  is  the  equivalent  option  to  -H,  --header but is for proxy
              communication only like in CONNECT requests when you want a separate header sent to the  proxy  to
              what is sent to the actual remote host.

              curl  will  make sure that each header you add/replace is sent with the proper end-of-line marker,
              you should thus not add that as a part of the header content: do  not  add  newlines  or  carriage
              returns, they will only mess things up for you.

              Headers  specified  with  this option will not be included in requests that curl knows will not be
              sent to a proxy.

              Starting in 7.55.0, this option can take an argument in @filename style, which then adds a  header
              for each line in the input file. Using @- will make curl read the header file from stdin.

              This option can be used multiple times to add/replace/remove multiple headers.

              Added in 7.37.0.

       --proxy-insecure
              Same as -k, --insecure but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-key-type <type>
              Same as --key-type but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-key <key>
              Same as --key but used in HTTPS proxy context.

       --proxy-negotiate
              Tells  curl to use HTTP Negotiate (SPNEGO) authentication when communicating with the given proxy.
              Use --negotiate for enabling HTTP Negotiate (SPNEGO) with a remote host.

              See also --proxy-anyauth and --proxy-basic. Added in 7.17.1.

       --proxy-ntlm
              Tells curl to use HTTP NTLM authentication when communicating with the given proxy. Use --ntlm for
              enabling NTLM with a remote host.

              See also --proxy-negotiate and --proxy-anyauth.

       --proxy-pass <phrase>
              Same as --pass but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-service-name <name>
              This option allows you to change the service name for proxy negotiation.

              Added in 7.43.0.

       --proxy-ssl-allow-beast
              Same as --ssl-allow-beast but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlsauthtype <type>
              Same as --tlsauthtype but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlspassword <string>
              Same as --tlspassword but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlsuser <name>
              Same as --tlsuser but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlsv1
              Same as -1, --tlsv1 but used in HTTPS proxy context.

              Added in 7.52.0.

       -U, --proxy-user <user:password>
              Specify the user name and password to use for proxy authentication.

              If you use a Windows SSPI-enabled curl binary and do either Negotiate or NTLM authentication  then
              you  can  tell  curl  to  select  the user name and password from your environment by specifying a
              single colon with this option: "-U :".

              If this option is used several times, the last one will be used.

       -x, --proxy [protocol://]host[:port]
              Use the specified proxy.

              The proxy string can be specified with a protocol:// prefix. No protocol specified or http:// will
              be treated as HTTP proxy. Use socks4://, socks4a://, socks5:// or socks5h:// to request a specific
              SOCKS version to be used.  (The protocol support was added in curl 7.21.7)

              HTTPS proxy support via https:// protocol prefix was added in 7.52.0 for OpenSSL, GnuTLS and NSS.

              Unrecognized and unsupported proxy protocols cause an error  since  7.52.0.   Prior  versions  may
              ignore the protocol and use http:// instead.

              If the port number is not specified in the proxy string, it is assumed to be 1080.

              This  option  overrides  existing  environment  variables that set the proxy to use. If there's an
              environment variable setting a proxy, you can set proxy to "" to override it.

              All operations that are performed over an HTTP proxy will transparently be converted to  HTTP.  It
              means  that  certain  protocol specific operations might not be available. This is not the case if
              you can tunnel through the proxy, as one with the -p, --proxytunnel option.

              User and password that might be provided in the proxy string are URL decoded by curl. This  allows
              you to pass in special characters such as @ by using %40 or pass in a colon with %3a.

              The  proxy  host can be specified the exact same way as the proxy environment variables, including
              the protocol prefix (http://) and the embedded user + password.

              If this option is used several times, the last one will be used.

       --proxy1.0 <host[:port]>
              Use the specified HTTP 1.0 proxy. If the port number is not specified, it is assumed at port 1080.

              The only difference between this and the HTTP proxy option -x, --proxy, is that  attempts  to  use
              CONNECT through the proxy will specify an HTTP 1.0 protocol instead of the default HTTP 1.1.

       -p, --proxytunnel
              When  an  HTTP  proxy is used -x, --proxy, this option will cause non-HTTP protocols to attempt to
              tunnel through the proxy instead of merely  using  it  to  do  HTTP-like  operations.  The  tunnel
              approach  is  made  with  the HTTP proxy CONNECT request and requires that the proxy allows direct
              connect to the remote port number curl wants to tunnel through to.

              To suppress proxy CONNECT response headers when curl is set  to  output  headers  use  --suppress-
              connect-headers.

              See also -x, --proxy.

       --pubkey <key>
              (SFTP SCP) Public key file name. Allows you to provide your public key in this separate file.

              If this option is used several times, the last one will be used.

              (As of 7.39.0, curl attempts to automatically extract the public key from the private key file, so
              passing  this  option  is  generally  not  required. Note that this public key extraction requires
              libcurl to be linked against a copy of libssh2 1.2.8 or  higher  that  is  itself  linked  against
              OpenSSL.)

       -Q, --quote
              (FTP  SFTP)  Send  an  arbitrary command to the remote FTP or SFTP server. Quote commands are sent
              BEFORE the transfer takes place (just after the initial PWD command in  an  FTP  transfer,  to  be
              exact).  To make commands take place after a successful transfer, prefix them with a dash '-'.  To
              make commands be sent after curl has changed the  working  directory,  just  before  the  transfer
              command(s),  prefix  the  command with a '+' (this is only supported for FTP). You may specify any
              number of commands.

              If the server returns failure for one of the commands, the entire operation will be  aborted.  You
              must  send  syntactically  correct  FTP  commands as RFC 959 defines to FTP servers, or one of the
              commands listed below to SFTP servers.

              This option can be used multiple times. When speaking to an FTP server, prefix the command with an
              asterisk (*) to make curl continue even if the command fails as by default curl will stop at first
              failure.

              SFTP is a binary protocol. Unlike for FTP, curl  interprets  SFTP  quote  commands  itself  before
              sending  them  to  the  server.   File  names may be quoted shell-style to embed spaces or special
              characters.  Following is the list of all supported SFTP quote commands:

              chgrp group file
                     The chgrp command sets the group ID of the file named by the file operand to the  group  ID
                     specified by the group operand. The group operand is a decimal integer group ID.

              chmod mode file
                     The chmod command modifies the file mode bits of the specified file. The mode operand is an
                     octal integer mode number.

              chown user file
                     The  chown  command  sets  the  owner  of the file named by the file operand to the user ID
                     specified by the user operand. The user operand is a decimal integer user ID.

              ln source_file target_file
                     The ln and symlink commands create a symbolic link at the target_file location pointing  to
                     the source_file location.

              mkdir directory_name
                     The mkdir command creates the directory named by the directory_name operand.

              pwd    The pwd command returns the absolute pathname of the current working directory.

              rename source target
                     The  rename  command  renames  the  file  or  directory  named by the source operand to the
                     destination path named by the target operand.

              rm file
                     The rm command removes the file specified by the file operand.

              rmdir directory
                     The rmdir command removes the directory entry specified by the directory operand,  provided
                     it is empty.

              symlink source_file target_file
                     See ln.

       --random-file <file>
              Specify  the  path name to file containing what will be considered as random data. The data may be
              used to seed the random engine for SSL connections.  See also the --egd-file option.

       -r, --range <range>
              (HTTP FTP SFTP FILE) Retrieve a byte range (i.e a partial document) from a HTTP/1.1, FTP  or  SFTP
              server or a local FILE. Ranges can be specified in a number of ways.

              0-499     specifies the first 500 bytes

              500-999   specifies the second 500 bytes

              -500      specifies the last 500 bytes

              9500-     specifies the bytes from offset 9500 and forward

              0-0,-1    specifies the first and last byte only(*)(HTTP)

              100-199,500-599
                        specifies two separate 100-byte ranges(*) (HTTP)

              (*) = NOTE that this will cause the server to reply with a multipart response!

              Only  digit  characters (0-9) are valid in the 'start' and 'stop' fields of the 'start-stop' range
              syntax. If a non-digit character is given in the range, the server's response will be unspecified,
              depending on the server's configuration.

              You should also be aware that many HTTP/1.1 servers do not have this feature enabled, so that when
              you attempt to get a range, you'll instead get the whole document.

              FTP and SFTP range downloads only support the simple 'start-stop' syntax (optionally with  one  of
              the numbers omitted). FTP use depends on the extended FTP command SIZE.

              If this option is used several times, the last one will be used.

       --raw  (HTTP)  When  used,  it  disables  all internal HTTP decoding of content or transfer encodings and
              instead makes them passed on unaltered, raw.

              Added in 7.16.2.

       -e, --referer <URL>
              (HTTP) Sends the "Referrer Page" information to the HTTP server. This can also be set with the -H,
              --header flag of course.  When used with  -L,  --location  you  can  append  ";auto"  to  the  -e,
              --referer  URL to make curl automatically set the previous URL when it follows a Location: header.
              The ";auto" string can be used alone, even if you don't set an initial -e, --referer.

              If this option is used several times, the last one will be used.

              See also -A, --user-agent and -H, --header.

       -J, --remote-header-name
              (HTTP) This option tells the  -O,  --remote-name  option  to  use  the  server-specified  Content-
              Disposition filename instead of extracting a filename from the URL.

              If  the  server  specifies  a  file  name  and a file with that name already exists in the current
              working directory it will not be overwritten and an  error  will  occur.  If  the  server  doesn't
              specify a file name then this option has no effect.

              There's  no  attempt  to  decode  %-sequences  (yet) in the provided file name, so this option may
              provide you with rather unexpected file names.

              WARNING: Exercise judicious use of this option, especially on Windows. A rogue server  could  send
              you the name of a DLL or other file that could possibly be loaded automatically by Windows or some
              third party software.

       --remote-name-all
              This option changes the default action for all given URLs to be dealt with as if -O, --remote-name
              were  used for each one. So if you want to disable that for a specific URL after --remote-name-all
              has been used, you must use "-o -" or --no-remote-name.

              Added in 7.19.0.

       -O, --remote-name
              Write output to a local file named like the remote file we get. (Only the file part of the  remote
              file is used, the path is cut off.)

              The file will be saved in the current working directory. If you want the file saved in a different
              directory,  make  sure  you  change  the  current working directory before invoking curl with this
              option.

              The remote file name to use for saving is extracted from the given URL, nothing else,  and  if  it
              already  exists  it will be overwritten. If you want the server to be able to choose the file name
              refer to -J, --remote-header-name which can be used in addition to  this  option.  If  the  server
              chooses a file name and that name already exists it will not be overwritten.

              There  is  no  URL decoding done on the file name. If it has %20 or other URL encoded parts of the
              name, they will end up as-is as file name.

              You may use this option as many times as the number of URLs you have.

       -R, --remote-time
              When used, this will make curl attempt to figure out the timestamp of the remote file, and if that
              is available make the local file get that same timestamp.

       --request-target
              (HTTP) Tells curl to use an alternative "target" (path) instead of using the path as  provided  in
              the  URL.  Particularly  useful when wanting to issue HTTP requests without leading slash or other
              data that doesn't follow the regular URL pattern, like "OPTIONS *".

              Added in 7.55.0.

       -X, --request <command>
              (HTTP) Specifies a custom request method to use when communicating  with  the  HTTP  server.   The
              specified  request  method  will  be  used instead of the method otherwise used (which defaults to
              GET). Read the HTTP 1.1  specification  for  details  and  explanations.  Common  additional  HTTP
              requests  include PUT and DELETE, but related technologies like WebDAV offers PROPFIND, COPY, MOVE
              and more.

              Normally you don't need this option. All sorts of GET, HEAD, POST  and  PUT  requests  are  rather
              invoked by using dedicated command line options.

              This  option only changes the actual word used in the HTTP request, it does not alter the way curl
              behaves. So for example if you want to make a proper HEAD request, using -X HEAD will not suffice.
              You need to use the -I, --head option.

              The method string you set with -X, --request will be used for  all  requests,  which  if  you  for
              example  use  -L,  --location  may  cause unintended side-effects when curl doesn't change request
              method according to the HTTP 30x response codes - and similar.

              (FTP) Specifies a custom FTP command to use instead of LIST when doing file lists with FTP.

              (POP3) Specifies a custom POP3 command to use instead of LIST or RETR. (Added in 7.26.0)

              (IMAP) Specifies a custom IMAP command to use instead of LIST. (Added in 7.30.0)

              (SMTP) Specifies a custom SMTP command to use instead of HELP or VRFY. (Added in 7.34.0)

              If this option is used several times, the last one will be used.

       --resolve <host:port:address>
              Provide a custom address for a specific host and port pair. Using this,  you  can  make  the  curl
              requests(s)  use  a  specified  address  and prevent the otherwise normally resolved address to be
              used. Consider it a sort of /etc/hosts alternative provided on the command line. The  port  number
              should  be  the number used for the specific protocol the host will be used for. It means you need
              several entries if you want to provide address for the same host but different ports.

              The provided address set by this option will be used even if -4, --ipv4 or -6, --ipv6  is  set  to
              make curl use another IP version.

              Support for providing the IP address within [brackets] was added in 7.57.0.

              This option can be used many times to add many host names to resolve.

              Added in 7.21.3.

       --retry-connrefused
              In  addition  to the other conditions, consider ECONNREFUSED as a transient error too for --retry.
              This option is used together with --retry.

              Added in 7.52.0.

       --retry-delay <seconds>
              Make curl sleep this amount of time before each retry when a transfer has failed with a  transient
              error  (it  changes  the  default  backoff  time  algorithm  between retries). This option is only
              interesting if --retry is also used. Setting this delay to zero will make  curl  use  the  default
              backoff time.

              If this option is used several times, the last one will be used.

              Added in 7.12.3.

       --retry-max-time <seconds>
              The  retry  timer  is  reset before the first transfer attempt. Retries will be done as usual (see
              --retry) as long as the timer hasn't reached this given limit. Notice that  if  the  timer  hasn't
              reached  the  limit,  the  request will be made and while performing, it may take longer than this
              given time period. To limit a single request´s maximum time, use -m, --max-time.  Set this  option
              to zero to not timeout retries.

              If this option is used several times, the last one will be used.

              Added in 7.12.3.

       --retry <num>
              If  a transient error is returned when curl tries to perform a transfer, it will retry this number
              of times before giving up. Setting the number to  0  makes  curl  do  no  retries  (which  is  the
              default).  Transient  error  means  either:  a  timeout,  an  FTP 4xx response code or an HTTP 5xx
              response code.

              When curl is about to retry a transfer, it will first wait one second and then for all forthcoming
              retries it will double the waiting time until it reaches 10 minutes which then will be  the  delay
              between  the  rest  of  the  retries.  By using --retry-delay you disable this exponential backoff
              algorithm. See also --retry-max-time to limit the total time allowed for retries.

              If this option is used several times, the last one will be used.

              Added in 7.12.3.

       --sasl-ir
              Enable initial response in SASL authentication.

              Added in 7.31.0.

       --service-name <name>
              This option allows you to change the service name for SPNEGO.

              Examples: --negotiate --service-name sockd would use sockd/server-name.

              Added in 7.43.0.

       -S, --show-error
              When used with -s, --silent, it makes curl show an error message if it fails.

       -s, --silent
              Silent or quiet mode. Don't show progress meter or error messages.  Makes Curl mute. It will still
              output the data you ask for, potentially even to the terminal/stdout unless you redirect it.

              Use -S, --show-error in addition to this option to disable progress meter  but  still  show  error
              messages.

              See also -v, --verbose and --stderr.

       --socks4 <host[:port]>
              Use the specified SOCKS4 proxy. If the port number is not specified, it is assumed at port 1080.

              This option overrides any previous use of -x, --proxy, as they are mutually exclusive.

              Since  7.21.7,  this  option  is superfluous since you can specify a socks4 proxy with -x, --proxy
              using a socks4:// protocol prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at the same time -x, --proxy is used
              with an HTTP/HTTPS proxy. In such a case curl first connects to the SOCKS proxy and then  connects
              (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              Added in 7.15.2.

       --socks4a <host[:port]>
              Use the specified SOCKS4a proxy. If the port number is not specified, it is assumed at port 1080.

              This option overrides any previous use of -x, --proxy, as they are mutually exclusive.

              Since  7.21.7,  this  option is superfluous since you can specify a socks4a proxy with -x, --proxy
              using a socks4a:// protocol prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at the same time -x, --proxy is used
              with an HTTP/HTTPS proxy. In such a case curl first connects to the SOCKS proxy and then  connects
              (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              Added in 7.18.0.

       --socks5-basic
              Tells  curl  to  use  username/password  authentication  when  connecting  to a SOCKS5 proxy.  The
              username/password authentication is enabled by default.   Use  --socks5-gssapi  to  force  GSS-API
              authentication to SOCKS5 proxies.

              Added in 7.55.0.

       --socks5-gssapi-nec
              As  part  of  the  GSS-API  negotiation  a protection mode is negotiated. RFC 1961 says in section
              4.3/4.4 it should be protected, but  the  NEC  reference  implementation  does  not.   The  option
              --socks5-gssapi-nec allows the unprotected exchange of the protection mode negotiation.

              Added in 7.19.4.

       --socks5-gssapi-service <name>
              The  default service name for a socks server is rcmd/server-fqdn. This option allows you to change
              it.

              Examples: --socks5 proxy-name --socks5-gssapi-service sockd would  use  sockd/proxy-name  --socks5
              proxy-name  --socks5-gssapi-service  sockd/real-name would use sockd/real-name for cases where the
              proxy-name does not match the principal name.

              Added in 7.19.4.

       --socks5-gssapi
              Tells curl to use  GSS-API  authentication  when  connecting  to  a  SOCKS5  proxy.   The  GSS-API
              authentication   is  enabled  by  default  (if  curl  is  compiled  with  GSS-API  support).   Use
              --socks5-basic to force username/password authentication to SOCKS5 proxies.

              Added in 7.55.0.

       --socks5-hostname <host[:port]>
              Use the specified SOCKS5 proxy (and let the proxy resolve the host name). If the  port  number  is
              not specified, it is assumed at port 1080.

              This option overrides any previous use of -x, --proxy, as they are mutually exclusive.

              Since  7.21.7,  this  option is superfluous since you can specify a socks5 hostname proxy with -x,
              --proxy using a socks5h:// protocol prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at the same time -x, --proxy is used
              with an HTTP/HTTPS proxy. In such a case curl first connects to the SOCKS proxy and then  connects
              (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              Added in 7.18.0.

       --socks5 <host[:port]>
              Use  the  specified  SOCKS5  proxy  - but resolve the host name locally. If the port number is not
              specified, it is assumed at port 1080.

              This option overrides any previous use of -x, --proxy, as they are mutually exclusive.

              Since 7.21.7, this option is superfluous since you can specify a socks5  proxy  with  -x,  --proxy
              using a socks5:// protocol prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at the same time -x, --proxy is used
              with  an HTTP/HTTPS proxy. In such a case curl first connects to the SOCKS proxy and then connects
              (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              This option (as well as --socks4) does not work with IPV6, FTPS or LDAP.

              Added in 7.18.0.

       -Y, --speed-limit <speed>
              If a download is slower than this given speed (in bytes per second) for speed-time seconds it gets
              aborted. speed-time is set with -y, --speed-time and is 30 if not set.

              If this option is used several times, the last one will be used.

       -y, --speed-time <seconds>
              If a download is slower than speed-limit bytes per second during a speed-time period, the download
              gets aborted. If speed-time is used, the default  speed-limit  will  be  1  unless  set  with  -Y,
              --speed-limit.

              This  option  controls  transfers and thus will not affect slow connects etc. If this is a concern
              for you, try the --connect-timeout option.

              If this option is used several times, the last one will be used.

       --ssl-allow-beast
              This option tells curl to not work around a security flaw in the SSL3 and TLS1.0  protocols  known
              as  BEAST.   If  this  option  isn't  used,  the  SSL  layer  may  use  workarounds known to cause
              interoperability problems with some older SSL implementations. WARNING: this  option  loosens  the
              SSL security, and by using this flag you ask for exactly that.

              Added in 7.25.0.

       --ssl-no-revoke
              (WinSSL)  This  option  tells curl to disable certificate revocation checks.  WARNING: this option
              loosens the SSL security, and by using this flag you ask for exactly that.

              Added in 7.44.0.

       --ssl-reqd
              (FTP IMAP POP3 SMTP) Require SSL/TLS for the connection.  Terminates the connection if the  server
              doesn't support SSL/TLS.

              This option was formerly known as --ftp-ssl-reqd.

              Added in 7.20.0.

       --ssl  (FTP IMAP POP3 SMTP) Try to use SSL/TLS for the connection.  Reverts to a non-secure connection if
              the  server  doesn't  support  SSL/TLS.   See  also --ftp-ssl-control and --ssl-reqd for different
              levels of encryption required.

              This option was formerly known as --ftp-ssl (Added in 7.11.0). That option name can still be  used
              but will be removed in a future version.

              Added in 7.20.0.

       -2, --sslv2
              (SSL)  Forces  curl to use SSL version 2 when negotiating with a remote SSL server. Sometimes curl
              is built without SSLv2 support. SSLv2 is widely considered insecure (see RFC 6176).

              See also --http1.1 and --http2. -2, --sslv2 requires that the  underlying  libcurl  was  built  to
              support TLS. This option overrides -3, --sslv3 and -1, --tlsv1 and --tlsv1.1 and --tlsv1.2.

       -3, --sslv3
              (SSL)  Forces  curl to use SSL version 3 when negotiating with a remote SSL server. Sometimes curl
              is built without SSLv3 support. SSLv3 is widely considered insecure (see RFC 7568).

              See also --http1.1 and --http2. -3, --sslv3 requires that the  underlying  libcurl  was  built  to
              support TLS. This option overrides -2, --sslv2 and -1, --tlsv1 and --tlsv1.1 and --tlsv1.2.

       --stderr
              Redirect  all  writes to stderr to the specified file instead. If the file name is a plain '-', it
              is instead written to stdout.

              If this option is used several times, the last one will be used.

              See also -v, --verbose and -s, --silent.

       --suppress-connect-headers
              When -p, --proxytunnel is used and a CONNECT request is made don't output proxy  CONNECT  response
              headers. This option is meant to be used with -D, --dump-header or -i, --include which are used to
              show  protocol  headers  in the output. It has no effect on debug options such as -v, --verbose or
              --trace, or any statistics.

              See also -D, --dump-header and -i, --include and -p, --proxytunnel.

       --tcp-fastopen
              Enable use of TCP Fast Open (RFC7413).

              Added in 7.49.0.

       --tcp-nodelay
              Turn on the TCP_NODELAY option. See the  curl_easy_setopt(3)  man  page  for  details  about  this
              option.

              Since  7.50.2,  curl  sets  this option by default and you need to explicitly switch it off if you
              don't want it on.

              Added in 7.11.2.

       -t, --telnet-option <opt=val>
              Pass options to the telnet protocol. Supported options are:

              TTYPE=<term> Sets the terminal type.

              XDISPLOC=<X display> Sets the X display location.

              NEW_ENV=<var,val> Sets an environment variable.

       --tftp-blksize <value>
              (TFTP) Set TFTP BLKSIZE option (must be >512). This is the block size that curl will  try  to  use
              when transferring data to or from a TFTP server. By default 512 bytes will be used.

              If this option is used several times, the last one will be used.

              Added in 7.20.0.

       --tftp-no-options
              (TFTP) Tells curl not to send TFTP options requests.

              This  option  improves  interop  with  some  legacy  servers  that  do not acknowledge or properly
              implement TFTP options. When this option is used --tftp-blksize is ignored.

              Added in 7.48.0.

       -z, --time-cond <time>
              (HTTP FTP) Request a file that has been modified later than the given time and date, or  one  that
              has  been  modified before that time. The <date expression> can be all sorts of date strings or if
              it doesn't match any internal ones, it is taken as a filename and tries to  get  the  modification
              date (mtime) from <file> instead. See the curl_getdate(3) man pages for date expression details.

              Start the date expression with a dash (-) to make it request for a document that is older than the
              given date/time, default is a document that is newer than the specified date/time.

              If this option is used several times, the last one will be used.

       --tls-max <VERSION>
              (SSL)  VERSION defines maximum supported TLS version. A minimum is defined by arguments tlsv1.0 or
              tlsv1.1 or tlsv1.2.

              default
                     Use up to recommended TLS version.

              1.0    Use up to TLSv1.0.

              1.1    Use up to TLSv1.1.

              1.2    Use up to TLSv1.2.

              1.3    Use up to TLSv1.3.

       See also --tlsv1.0 and --tlsv1.1 and --tlsv1.2. --tls-max requires that the underlying libcurl was  built
       to support TLS. Added in 7.54.0.

       --tlsauthtype <type>
              Set  TLS  authentication  type.  Currently,  the  only supported option is "SRP", for TLS-SRP (RFC
              5054). If --tlsuser and --tlspassword are specified but --tlsauthtype is  not,  then  this  option
              defaults to "SRP".

              Added in 7.21.4.

       --tlspassword
              Set  password  for  use  with the TLS authentication method specified with --tlsauthtype. Requires
              that --tlsuser also be set.

              Added in 7.21.4.

       --tlsuser <name>
              Set username for use with the TLS authentication method  specified  with  --tlsauthtype.  Requires
              that --tlspassword also is set.

              Added in 7.21.4.

       --tlsv1.0
              (TLS) Forces curl to use TLS version 1.0 when connecting to a remote TLS server.

              Added in 7.34.0.

       --tlsv1.1
              (TLS) Forces curl to use TLS version 1.1 when connecting to a remote TLS server.

              Added in 7.34.0.

       --tlsv1.2
              (TLS) Forces curl to use TLS version 1.2 when connecting to a remote TLS server.

              Added in 7.34.0.

       --tlsv1.3
              (TLS) Forces curl to use TLS version 1.3 when connecting to a remote TLS server.

              Note that TLS 1.3 is only supported by a subset of TLS backends. At the time of this writing, they
              are BoringSSL, NSS, and Secure Transport (on iOS 11 or later, and macOS 10.13 or later).

              Added in 7.52.0.

       -1, --tlsv1
              (SSL)  Tells curl to use TLS version 1.x when negotiating with a remote TLS server. That means TLS
              version 1.0, 1.1 or 1.2.

              See also --http1.1 and --http2. -1, --tlsv1 requires that the  underlying  libcurl  was  built  to
              support TLS. This option overrides --tlsv1.1 and --tlsv1.2 and --tlsv1.3.

       --tr-encoding
              (HTTP)  Request a compressed Transfer-Encoding response using one of the algorithms curl supports,
              and uncompress the data while receiving it.

              Added in 7.21.6.

       --trace-ascii <file>
              Enables a full trace dump of all incoming and outgoing data, including descriptive information, to
              the given output file. Use "-" as filename to have the output sent to stdout.

              This is very similar to --trace, but leaves out the hex part and only shows the ASCII part of  the
              dump. It makes smaller output that might be easier to read for untrained humans.

              If this option is used several times, the last one will be used.

              This option overrides --trace and -v, --verbose.

       --trace-time
              Prepends a time stamp to each trace or verbose line that curl displays.

              Added in 7.14.0.

       --trace <file>
              Enables a full trace dump of all incoming and outgoing data, including descriptive information, to
              the  given output file. Use "-" as filename to have the output sent to stdout. Use "%" as filename
              to have the output sent to stderr.

              If this option is used several times, the last one will be used.

              This option overrides -v, --verbose and --trace-ascii.

       --unix-socket <path>
              (HTTP) Connect through this Unix domain socket, instead of using the network.

              Added in 7.40.0.

       -T, --upload-file <file>
              This transfers the specified local file to the remote URL.  If  there  is  no  file  part  in  the
              specified  URL,  curl  will append the local file name. NOTE that you must use a trailing / on the
              last directory to really prove to Curl that there is no file name or curl  will  think  that  your
              last  directory  name  is  the  remote  file  name  to use. That will most likely cause the upload
              operation to fail. If this is used on an HTTP(S) server, the PUT command will be used.

              Use the file name "-" (a single dash) to use stdin instead of a given file.  Alternately, the file
              name "." (a single period) may be specified instead of "-" to use stdin in  non-blocking  mode  to
              allow reading server output while stdin is being uploaded.

              You  can  specify one -T, --upload-file for each URL on the command line. Each -T, --upload-file +
              URL pair specifies what to upload and to where. curl also supports "globbing" of the -T, --upload-
              file argument, meaning that you can upload multiple files to a single URL by using  the  same  URL
              globbing style supported in the URL, like this:

               curl --upload-file "{file1,file2}" http://www.example.com

              or even

               curl -T "img[1-1000].png" ftp://ftp.example.com/upload/

              When uploading to an SMTP server: the uploaded data is assumed to be RFC 5322 formatted. It has to
              feature  the  necessary  set of headers and mail body formatted correctly by the user as curl will
              not transcode nor encode it further in any way.

       --url <url>
              Specify a URL to fetch. This option is mostly handy when you want to specify URL(s)  in  a  config
              file.

              If  the given URL is missing a scheme name (such as "http://" or "ftp://" etc) then curl will make
              a guess based on the host. If the outermost sub-domain name matches DICT, FTP, IMAP, LDAP, POP3 or
              SMTP then that protocol will be used, otherwise HTTP will be used. Since 7.45.0  guessing  can  be
              disabled by setting a default protocol, see --proto-default for details.

              This  option  may  be  used any number of times. To control where this URL is written, use the -o,
              --output or the -O, --remote-name options.

       -B, --use-ascii
              (FTP LDAP) Enable ASCII transfer. For FTP, this can also be enforced by using a URL that ends with
              ";type=A". This option causes data sent to stdout to be in text mode for win32 systems.

       -A, --user-agent <name>
              (HTTP) Specify the User-Agent string to send to the HTTP server. To encode blanks in  the  string,
              surround  the string with single quote marks. This can also be set with the -H, --header option of
              course.

              If this option is used several times, the last one will be used.

       -u, --user <user:password>
              Specify the user name and password to use for server authentication.  Overrides  -n,  --netrc  and
              --netrc-optional.

              If you simply specify the user name, curl will prompt for a password.

              The  user  name  and passwords are split up on the first colon, which makes it impossible to use a
              colon in the user name with this option. The password can, still.

              When using Kerberos V5 with a Windows based server you should include the Windows domain  name  in
              the user name, in order for the server to successfully obtain a Kerberos Ticket. If you don't then
              the initial authentication handshake may fail.

              When  using  NTLM,  the user name can be specified simply as the user name, without the domain, if
              there is a single domain and forest in your setup for example.

              To specify the domain name use either Down-Level Logon Name or UPN (User Principal Name)  formats.
              For example, EXAMPLE\user and user@example.com respectively.

              If  you  use a Windows SSPI-enabled curl binary and perform Kerberos V5, Negotiate, NTLM or Digest
              authentication then you can tell curl to select the user name and password from  your  environment
              by specifying a single colon with this option: "-u :".

              If this option is used several times, the last one will be used.

       -v, --verbose
              Makes  curl  verbose  during the operation. Useful for debugging and seeing what's going on "under
              the hood". A line starting with '>' means "header data" sent by  curl,  '<'  means  "header  data"
              received  by  curl  that  is hidden in normal cases, and a line starting with '*' means additional
              info provided by curl.

              If you only want HTTP headers in the output, -i, --include might be the option you're looking for.

              If you think this option still doesn't give you enough details, consider using --trace or --trace-
              ascii instead.

              Use -s, --silent to make curl really quiet.

              See also -i, --include. This option overrides --trace and --trace-ascii.

       -V, --version
              Displays information about curl and the libcurl version it uses.

              The first line includes the full version of curl, libcurl and other  3rd  party  libraries  linked
              with the executable.

              The second line (starts with "Protocols:") shows all protocols that libcurl reports to support.

              The  third  line  (starts  with  "Features:")  shows  specific  features libcurl reports to offer.
              Available features include:

              IPv6   You can use IPv6 with this.

              krb4   Krb4 for FTP is supported.

              SSL    SSL versions of various protocols are supported, such as HTTPS, FTPS, POP3S and so on.

              libz   Automatic decompression of compressed files over HTTP is supported.

              NTLM   NTLM authentication is supported.

              Debug  This curl uses a libcurl built with Debug. This  enables  more  error-tracking  and  memory
                     debugging etc. For curl-developers only!

              AsynchDNS
                     This  curl  uses  asynchronous  name resolves. Asynchronous name resolves can be done using
                     either the c-ares or the threaded resolver backends.

              SPNEGO SPNEGO authentication is supported.

              Largefile
                     This curl supports transfers of large files, files larger than 2GB.

              IDN    This curl supports IDN - international domain names.

              GSS-API
                     GSS-API is supported.

              SSPI   SSPI is supported.

              TLS-SRP
                     SRP (Secure Remote Password) authentication is supported for TLS.

              HTTP2  HTTP/2 support has been built-in.

              UnixSockets
                     Unix sockets support is provided.

              HTTPS-proxy
                     This curl is built to support HTTPS proxy.

              Metalink
                     This curl supports Metalink (both version 3 and 4 (RFC 5854)), which describes mirrors  and
                     hashes.  curl will use mirrors for failover if there are errors (such as the file or server
                     not being available).

              PSL    PSL  is short for Public Suffix List and means that this curl has been built with knowledge
                     about "public suffixes".

       -w, --write-out <format>
              Make curl display information on stdout after a completed transfer. The format is  a  string  that
              may  contain  plain  text  mixed  with  any  number of variables. The format can be specified as a
              literal "string", or you can have curl read the format from a file with "@filename"  and  to  tell
              curl to read the format from stdin you write "@-".

              The  variables  present  in  the  output format will be substituted by the value or text that curl
              thinks fit, as described below. All variables are specified as %{variable_name} and  to  output  a
              normal  %  you just write them as %%. You can output a newline by using \n, a carriage return with
              \r and a tab space with \t.

              NOTE: The %-symbol is a special symbol in the win32-environment, where all occurrences of  %  must
              be doubled when using this option.

              The variables available are:

              content_type   The Content-Type of the requested document, if there was any.

              filename_effective
                             The  ultimate  filename that curl writes out to. This is only meaningful if curl is
                             told to write to a file with the -O, --remote-name or  -o,  --output  option.  It's
                             most  useful  in  combination  with  the -J, --remote-header-name option. (Added in
                             7.26.0)

              ftp_entry_path The initial path curl ended up in when logging on to the remote FTP server.  (Added
                             in 7.15.4)

              http_code      The  numerical response code that was found in the last retrieved HTTP(S) or FTP(s)
                             transfer. In 7.18.2 the alias response_code was added to show the same info.

              http_connect   The numerical code that was found in the last response (from a  proxy)  to  a  curl
                             CONNECT request. (Added in 7.12.4)

              http_version   The http version that was effectively used. (Added in 7.50.0)

              local_ip       The  IP  address  of  the  local  end of the most recently done connection - can be
                             either IPv4 or IPv6 (Added in 7.29.0)

              local_port     The local port number of the most recently done connection (Added in 7.29.0)

              num_connects   Number of new connects made in the recent transfer. (Added in 7.12.3)

              num_redirects  Number of redirects that were followed in the request. (Added in 7.12.3)

              proxy_ssl_verify_result
                             The result of  the  HTTPS  proxy's  SSL  peer  certificate  verification  that  was
                             requested. 0 means the verification was successful. (Added in 7.52.0)

              redirect_url   When  an  HTTP request was made without -L, --location to follow redirects (or when
                             --max-redir is met), this variable will show the actual URL a redirect  would  have
                             gone to. (Added in 7.18.2)

              remote_ip      The  remote IP address of the most recently done connection - can be either IPv4 or
                             IPv6 (Added in 7.29.0)

              remote_port    The remote port number of the most recently done connection (Added in 7.29.0)

              scheme         The URL scheme (sometimes called protocol) that  was  effectively  used  (Added  in
                             7.52.0)

              size_download  The total amount of bytes that were downloaded.

              size_header    The total amount of bytes of the downloaded headers.

              size_request   The total amount of bytes that were sent in the HTTP request.

              size_upload    The total amount of bytes that were uploaded.

              speed_download The  average download speed that curl measured for the complete download. Bytes per
                             second.

              speed_upload   The average upload speed that curl measured for  the  complete  upload.  Bytes  per
                             second.

              ssl_verify_result
                             The result of the SSL peer certificate verification that was requested. 0 means the
                             verification was successful. (Added in 7.19.0)

              time_appconnect
                             The   time,   in   seconds,   it   took   from  the  start  until  the  SSL/SSH/etc
                             connect/handshake to the remote host was completed. (Added in 7.19.0)

              time_connect   The time, in seconds, it took from the start until the TCP connect  to  the  remote
                             host (or proxy) was completed.

              time_namelookup
                             The  time,  in  seconds,  it  took  from  the  start  until  the name resolving was
                             completed.

              time_pretransfer
                             The time, in seconds, it took from the start until the file transfer was just about
                             to begin. This  includes  all  pre-transfer  commands  and  negotiations  that  are
                             specific to the particular protocol(s) involved.

              time_redirect  The  time,  in  seconds,  it  took for all redirection steps including name lookup,
                             connect, pretransfer  and  transfer  before  the  final  transaction  was  started.
                             time_redirect  shows  the complete execution time for multiple redirections. (Added
                             in 7.12.3)

              time_starttransfer
                             The time, in seconds, it took from the start until the first byte was just about to
                             be transferred. This includes time_pretransfer and also the time the server  needed
                             to calculate the result.

              time_total     The total time, in seconds, that the full operation lasted.

              url_effective  The  URL  that  was  fetched  last.  This is most meaningful if you've told curl to
                             follow location: headers.

              If this option is used several times, the last one will be used.

       --xattr
              When saving output to a file, this option tells curl to store certain file  metadata  in  extended
              file  attributes.  Currently, the URL is stored in the xdg.origin.url attribute and, for HTTP, the
              content type is stored in the mime_type attribute. If the file system does  not  support  extended
              attributes, a warning is issued.

FILES

       ~/.curlrc
              Default config file, see -K, --config for details.

ENVIRONMENT

       The  environment  variables  can  be  specified  in  lower case or upper case. The lower case version has
       precedence. http_proxy is an exception as it is only available in lower case.

       Using an environment variable to set the proxy has the same effect as using the -x, --proxy option.

       http_proxy [protocol://]<host>[:port]
              Sets the proxy server to use for HTTP.

       HTTPS_PROXY [protocol://]<host>[:port]
              Sets the proxy server to use for HTTPS.

       [url-protocol]_PROXY [protocol://]<host>[:port]
              Sets the proxy server to use for [url-protocol], where  the  protocol  is  a  protocol  that  curl
              supports and as specified in a URL. FTP, FTPS, POP3, IMAP, SMTP, LDAP etc.

       ALL_PROXY [protocol://]<host>[:port]
              Sets the proxy server to use if no protocol-specific proxy is set.

       NO_PROXY <comma-separated list of hosts>
              list  of host names that shouldn't go through any proxy. If set to a asterisk '*' only, it matches
              all hosts.

              Since 7.53.0, this environment variable disable the proxy even if specify -x, --proxy option. That
              is NO_PROXY=direct.example.com curl -x http://proxy.example.com http://direct.example.com accesses
              the  target  URL  directly,  and  NO_PROXY=direct.example.com  curl  -x   http://proxy.example.com
              http://somewhere.example.com accesses the target URL through proxy.

PROXY PROTOCOL PREFIXES

       Since  curl  version  7.21.7,  the  proxy  string  may  be specified with a protocol:// prefix to specify
       alternative proxy protocols.

       If no protocol is specified in the proxy string or if the string doesn't match a supported one, the proxy
       will be treated as an HTTP proxy.

       The supported proxy protocol prefixes are as follows:

       http://
              Makes it use it as a HTTP proxy. The default if no scheme prefix is used.

       https://
              Makes it treated as a HTTPS proxy.

       socks4://
              Makes it the equivalent of --socks4

       socks4a://
              Makes it the equivalent of --socks4a

       socks5://
              Makes it the equivalent of --socks5

       socks5h://
              Makes it the equivalent of --socks5-hostname

EXIT CODES

       There are a bunch of different error codes and their corresponding error messages that may appear  during
       bad conditions. At the time of this writing, the exit codes are:

       1      Unsupported protocol. This build of curl has no support for this protocol.

       2      Failed to initialize.

       3      URL malformed. The syntax was not correct.

       4      A  feature  or  option  that  was  needed  to  perform  the desired request was not enabled or was
              explicitly disabled at build-time. To make curl able to do this, you probably need  another  build
              of libcurl!

       5      Couldn't resolve proxy. The given proxy host could not be resolved.

       6      Couldn't resolve host. The given remote host was not resolved.

       7      Failed to connect to host.

       8      Weird server reply. The server sent data curl couldn't parse.

       9      FTP  access  denied.  The  server  denied  login  or  denied  access to the particular resource or
              directory you wanted to reach. Most often you tried to change to a directory that doesn't exist on
              the server.

       10     FTP accept failed. While waiting for the server to connect back when  an  active  FTP  session  is
              used, an error code was sent over the control connection or similar.

       11     FTP weird PASS reply. Curl couldn't parse the reply sent to the PASS request.

       12     During  an  active  FTP  session while waiting for the server to connect back to curl, the timeout
              expired.

       13     FTP weird PASV reply, Curl couldn't parse the reply sent to the PASV request.

       14     FTP weird 227 format. Curl couldn't parse the 227-line the server sent.

       15     FTP can't get host. Couldn't resolve the host IP we got in the 227-line.

       16     HTTP/2 error. A problem was detected in the HTTP2 framing layer. This is somewhat generic and  can
              be one out of several problems, see the error message for details.

       17     FTP couldn't set binary. Couldn't change transfer method to binary.

       18     Partial file. Only a part of the file was transferred.

       19     FTP couldn't download/access the given file, the RETR (or similar) command failed.

       21     FTP quote error. A quote command returned error from the server.

       22     HTTP  page  not retrieved. The requested url was not found or returned another error with the HTTP
              error code being 400 or above. This return code only appears if -f, --fail is used.

       23     Write error. Curl couldn't write data to a local filesystem or similar.

       25     FTP couldn't STOR file. The server denied the STOR operation, used for FTP uploading.

       26     Read error. Various reading problems.

       27     Out of memory. A memory allocation request failed.

       28     Operation timeout. The specified time-out period was reached according to the conditions.

       30     FTP PORT failed. The PORT command failed. Not all FTP servers support the PORT command, try  doing
              a transfer using PASV instead!

       31     FTP couldn't use REST. The REST command failed. This command is used for resumed FTP transfers.

       33     HTTP range error. The range "command" didn't work.

       34     HTTP post error. Internal post-request generation error.

       35     SSL connect error. The SSL handshaking failed.

       36     Bad download resume. Couldn't continue an earlier aborted download.

       37     FILE couldn't read file. Failed to open the file. Permissions?

       38     LDAP cannot bind. LDAP bind operation failed.

       39     LDAP search failed.

       41     Function not found. A required LDAP function was not found.

       42     Aborted by callback. An application told curl to abort the operation.

       43     Internal error. A function was called with a bad parameter.

       45     Interface error. A specified outgoing interface could not be used.

       47     Too many redirects. When following redirects, curl hit the maximum amount.

       48     Unknown  option  specified  to libcurl. This indicates that you passed a weird option to curl that
              was passed on to libcurl and rejected. Read up in the manual!

       49     Malformed telnet option.

       51     The peer's SSL certificate or SSH MD5 fingerprint was not OK.

       52     The server didn't reply anything, which here is considered an error.

       53     SSL crypto engine not found.

       54     Cannot set SSL crypto engine as default.

       55     Failed sending network data.

       56     Failure in receiving network data.

       58     Problem with the local certificate.

       59     Couldn't use specified SSL cipher.

       60     Peer certificate cannot be authenticated with known CA certificates.

       61     Unrecognized transfer encoding.

       62     Invalid LDAP URL.

       63     Maximum file size exceeded.

       64     Requested FTP SSL level failed.

       65     Sending the data requires a rewind that failed.

       66     Failed to initialise SSL Engine.

       67     The user name, password, or similar was not accepted and curl failed to log in.

       68     File not found on TFTP server.

       69     Permission problem on TFTP server.

       70     Out of disk space on TFTP server.

       71     Illegal TFTP operation.

       72     Unknown TFTP transfer ID.

       73     File already exists (TFTP).

       74     No such user (TFTP).

       75     Character conversion failed.

       76     Character conversion functions required.

       77     Problem with reading the SSL CA cert (path? access rights?).

       78     The resource referenced in the URL does not exist.

       79     An unspecified error occurred during the SSH session.

       80     Failed to shut down the SSL connection.

       82     Could not load CRL file, missing or wrong format (added in 7.19.0).

       83     Issuer check failed (added in 7.19.0).

       84     The FTP PRET command failed

       85     RTSP: mismatch of CSeq numbers

       86     RTSP: mismatch of Session Identifiers

       87     unable to parse FTP file list

       88     FTP chunk callback reported error

       89     No connection available, the session will be queued

       90     SSL public key does not matched pinned public key

       91     Invalid SSL certificate status.

       92     Stream error in HTTP/2 framing layer.

       XX     More error codes will appear here in future releases. The existing ones are meant to never change.

AUTHORS / CONTRIBUTORS

       Daniel Stenberg is the main author, but the whole list of contributors is found in  the  separate  THANKS
       file.

WWW

       https://curl.haxx.se

SEE ALSO

       ftp(1), wget(1)

Curl 7.58.0                                     November 16, 2016                                        curl(1)