Provided by: curl_7.35.0-1ubuntu2.20_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,  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.numericals.com/file[1-100].txt
        ftp://ftp.numericals.com/file[001-100].txt    (with leading zeros)
        ftp://ftp.letters.com/file[a-z].txt

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

        http://any.org/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://www.numericals.com/file[1-100:10].txt
        http://www.letters.com/file[a-z:2].txt

       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.

       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 [file] 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, -# is your friend.

OPTIONS

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

       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, --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.)

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

       -0, --http1.0
              (HTTP) Tells curl to use HTTP version 1.0 instead of using its internally preferred: HTTP 1.1.

       --http1.1
              (HTTP) Tells curl to use HTTP version 1.1. This is the internal default version. (Added in 7.33.0)

       --http2.0
              (HTTP)  Tells curl to issue its requests using HTTP 2.0. This requires that the underlying libcurl
              was built to support it. (Added in 7.33.0)

       -1, --tlsv1
              (SSL) Forces curl to use TLS version 1 when negotiating with a remote TLS server.

       -2, --sslv2
              (SSL) Forces curl to use SSL version 2 when negotiating with a remote SSL server.

       -3, --sslv3
              (SSL) Forces curl to use SSL version 3 when negotiating with a remote SSL server.

       -4, --ipv4
              If curl is capable of resolving an address  to  multiple  IP  versions  (which  it  is  if  it  is
              IPv6-capable), this option tells curl to resolve names to IPv4 addresses only.

       -6, --ipv6
              If  curl  is  capable  of  resolving  an  address  to  multiple  IP versions (which it is if it is
              IPv6-capable), this option tells curl to resolve names to IPv6 addresses only.

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

       -A, --user-agent <agent string>
              (HTTP) Specify the User-Agent string to send to the HTTP server. Some badly done CGIs fail if this
              field  isn't set to "Mozilla/4.0". 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.

       --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.

              Note  that  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.

       -b, --cookie <name=data>
              (HTTP) Pass the data to the HTTP server as a cookie. 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 line, it is treated as a filename to use to read previously stored
              cookie lines from, which should be used in this session if they  match.  Using  this  method  also
              activates the "cookie parser" which will make curl record incoming cookies too, which may be handy
              if you're using this in combination with the -L, --location option. The file format of the file to
              read cookies from should be plain HTTP headers or the Netscape/Mozilla cookie file format.

              NOTE that the file specified with -b, --cookie is only used as input. No cookies will be stored in
              the file. To store cookies, use the -c, --cookie-jar option  or  you  could  even  save  the  HTTP
              headers to a file using -D, --dump-header!

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

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

       --basic
              (HTTP) Tells curl to use HTTP Basic authentication. 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).

       -c, --cookie-jar <file name>
              (HTTP) Specify to which file you want curl to write all cookies after a completed operation.  Curl
              writes  all  cookies  previously  read  from a specified file as well as all cookies received from
              remote server(s). If no cookies are known, no file 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 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.

       -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.

       --ciphers <list of ciphers>
              (SSL)  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:
              http://www.openssl.org/docs/apps/ciphers.html

              NSS  ciphers  are done differently than OpenSSL and GnuTLS. The full list of NSS ciphers is in the
              NSSCipherSuite                 entry                 at                 this                  URL:
              http://git.fedorahosted.org/cgit/mod_nss.git/plain/docs/mod_nss.html#Directives

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

       --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.

       --connect-timeout <seconds>
              Maximum time in seconds that you allow the connection to the server to take.  This only limits the
              connection phase, once curl has connected this option is of  no  more  use.   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. See also the -m, --max-time option.

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

       --create-dirs
              When used in conjunction with the -o option,  curl  will  create  the  necessary  local  directory
              hierarchy  as  needed. This option creates the dirs mentioned with the -o option, nothing else. If
              the -o 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) Convert LF to CRLF in upload. Useful for MVS (OS/390).

       --crlfile <file>
              (HTTPS/FTPS) 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)

       -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.

              -d, --data is the same as --data-ascii. 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  'foobar' would thus be done with --data @foobar. When --data is told to read
              from a file like that, carriage returns and newlines will be stripped out.

       -D, --dump-header <file>
              Write the 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 however 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.

       --data-ascii <data>
              See -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 --data-ascii 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-urlencode <data>
              (HTTP) This posts data, similar to the other --data options with the exception that this  performs
              URL-encoding. (Added in 7.18.0)

              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.

       --delegation LEVEL
              Set  LEVEL  to  tell  the server what it is allowed to delegate when it comes to user credentials.
              Used with GSS/kerberos.

              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. See also --ntlm, --negotiate and --anyauth for
              related options.

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

       --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.

              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) 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.

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

       --dns-interface <interface>
              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).

              This option requires that libcurl was built with a resolver backend that supports this  operation.
              The c-ares backend is the only such one. (Added in 7.33.0)

       --dns-ipv4-addr <ip-address>
              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.

              This option requires that libcurl was built with a resolver backend that supports this  operation.
              The c-ares backend is the only such one.  (Added in 7.33.0)

       --dns-ipv6-addr <ip-address>
              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.

              This option requires that libcurl was built with a resolver backend that supports this  operation.
              The c-ares backend is the only such one.  (Added in 7.33.0)

       --dns-servers <ip-address,ip-address>
              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.

              This  option requires that libcurl was built with a resolver backend that supports this operation.
              The c-ares backend is the only such one.  (Added in 7.33.0)

       -e, --referer <URL>
              (HTTP) Sends the "Referer 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 --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 --referer.

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

       -E, --cert <certificate[:password]>
              (SSL) 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 private certificate concatenated! See --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 Mac OS X 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.

       --engine <name>
              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.

       --environment
              (RISC  OS  ONLY) Sets a range of environment variables, using the names the -w option supports, to
              allow easier extraction of useful information after having run curl.

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

       --cert-type <type>
              (SSL)  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.

       --cacert <CA certificate>
              (SSL) 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.

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

       --capath <CA certificate directory>
              (SSL) 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.

       -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).

       -F, --form <name=content>
              (HTTP) 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. 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 your password file to the server, where 'password' is the name of the  form-field
              to which /etc/passwd will be the input:

              curl -F password=@/etc/passwd www.mypasswords.com

              To  read  content  from stdin instead of a file, use - as the filename. This goes for both @ and <
              constructs.

              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" url.com

              or

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

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

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

              or

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

              See further examples and details in the MANUAL.

              This option can be used multiple times.

       --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. (Added in 7.13.0)

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

       --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.

       --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. (Added in 7.11.0)

              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.

       --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. (Added in 7.14.2)

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

       --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.x)

       --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 --ftp-ssl-ccc-mode for other modes.   (Added  in
              7.16.1)

       --ftp-ssl-ccc-mode [active/passive]
              (FTP)  Use  CCC  (Clear Command Channel) 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.  (Added in
              7.16.2)

       --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) that can still be used but will be removed in a future version.

       --form-string <name=string>
              (HTTP) Similar to --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 --form if there's any possibility that the  string  value  may  accidentally
              trigger the '@' or '<' features of --form.

       -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.

       -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, 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.

       -H, --header <header>
              (HTTP) Extra header to use when getting a web page. 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.

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

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

       --hostpubmd5 <md5>
              (SCP/SFTP)  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)

       --ignore-content-length
              (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.

       -i, --include
              (HTTP) Include the HTTP-header in the output. The HTTP-header includes  things  like  server-name,
              date of the document, HTTP-version and more...

       -I, --head
              (HTTP/FTP/FILE)  Fetch the HTTP-header 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.

       --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 http://www.netscape.com/

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

       -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.

       -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.

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

       -k, --insecure
              (SSL) This option explicitly allows curl to perform "insecure" SSL connections and transfers.  All
              SSL  connections  are  attempted to be made secure by using the CA certificate bundle installed by
              default. This makes all connections considered "insecure" fail unless -k, --insecure is used.

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

       -K, --config <config file>
              Specify which config file to read curl arguments from. The config file is a  text  file  in  which
              command  line  arguments  can  be  written  which then will be used as if they were written on the
              actual command line.

              Options and their parameters must be  specified  on  the  same  config  file  line,  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 = "http://curl.haxx.se/docs/"

              When  curl  is invoked, it always (unless -q 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 = "curl.haxx.se"
              output = "curlhere.html"
              user-agent = "superagent/1.0"

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

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

       --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. (Added in 7.18.0)

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

       --key <key>
              (SSL/SSH) Private key file name. Allows you to provide your private key in this separate file.

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

       --key-type <type>
              (SSL)  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.

       --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.

              This option requires a library built with kerberos4 or GSSAPI (GSS-Negotiate) support. This is not
              very common. Use -V, --version to see if your curl supports it.

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

       -l, --list-only
              (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 <command>, 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)

       -L, --location
              (HTTP/HTTPS)  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.

       --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. This feature is useful if you have a
              limited pipe and you'd like your transfer not to use your entire bandwidth.

              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.

              The given rate is the average speed counted during the entire transfer. It means that  curl  might
              use higher transfer speeds in short bursts, but over time it uses no more than the given rate.

              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.

       --local-port <num>[-num]
              Set a preferred number or range 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/HTTPS) 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).

       -m, --max-time <seconds>
              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.  See also the --connect-timeout option.

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

       --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.

              (Added in 7.25.0)

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

              (Added in 7.20.0)

       --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.

              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.

       --mail-rcpt <address>
              (SMTP) Specify a single address, user name or mailing list name.

              When performing a mail transfer, the recipient should specify a valid email address  to  send  the
              mail to. (Added in 7.20.0)

              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)

       --max-redirs <num>
              Set  maximum  number of redirection-followings allowed. If -L, --location is used, this option can
              be 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 limitless.

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

       --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 --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.

              (Added in 7.27.0, if built against the libmetalink library.)

       -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(4) or 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

       -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.

       --netrc-file
              This option is similar to --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, only the last one will be used.  (Added in 7.21.5)

              This option overrides any use of --netrc as they are mutually exclusive.  It will  also  abide  by
              --netrc-optional if specified.

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

       --negotiate
              (HTTP) Enables GSS-Negotiate authentication. The GSS-Negotiate method was  designed  by  Microsoft
              and  is  used  in  their  web  applications.  It  is  primarily  meant  as a support for Kerberos5
              authentication but may be also used along with another authentication method. For more information
              see IETF draft draft-brezak-spnego-http-04.txt.

              If you want to enable Negotiate for your proxy authentication, then use --proxy-negotiate.

              This  option  requires  a  library  built  with  GSSAPI  support. This is not very common. Use -V,
              --version to see if your version supports GSS-Negotiate.

              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
              option aren't actually used.

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

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

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

       --no-sessionid
              (SSL)  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. (Added in 7.16.0)

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

       --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.  (Added in 7.19.4).

       --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.

              This  option  requires  a  library  built  with SSL support. Use -V, --version to see if your curl
              supports NTLM.

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

              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.

       -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 remote file name to use for saving is extracted from the given URL, nothing else.

              Consequentially, the file will be saved in the current working directory. If  you  want  the  file
              saved  in  a different directory, make sure you change current working directory before you invoke
              curl with the -O, --remote-name flag!

              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.

       --oauth2-bearer
              (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.

       -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.

       -P, --ftp-port <address>
              (FTP) Reverses the default initiator/listener roles when connecting with FTP.  This  switch  makes
              curl  use  active  mode.  In  practice, 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++.

       Starting  in  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.

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

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

       --post301
              (HTTP)  Tells curl to respect RFC 2616/10.3.2 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 (Added  in
              7.17.1)

       --post302
              (HTTP)  Tells curl to respect RFC 2616/10.3.2 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 (Added  in
              7.19.1)

       --post303
              (HTTP)  Tells curl to respect RFC 2616/10.3.2 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 (Added  in
              7.26.0)

       --proto <protocols>
              Tells  curl to use the listed protocols for its initial retrieval. Protocols are evaluated left to
              right, are comma separated, and are each a protocol name or 'all', optionally prefixed by zero  or
              more modifiers. Available modifiers are:

              +  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.

              (Added in 7.20.2)

       --proto-redir <protocols>
              Tells curl to use the listed protocols after  a  redirect.  See  --proto  for  how  protocols  are
              represented.

              (Added in 7.20.2)

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

       --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.

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

       --proxy1.0 <proxyhost[: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.

       --pubkey <key>
              (SSH) 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.

       -q     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.

       -Q, --quote <command>
              (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.

       -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(*)(H)

              500-700,600-799
                        specifies 300 bytes from offset 500(H)

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

       (*) = 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.

       -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.

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

       --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)

       --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)

       --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.

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

              (Added in 7.21.3)

       --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.  (Added  in
              7.12.3)

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

       --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.  (Added in 7.12.3)

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

       --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. (Added in 7.12.3)

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

       -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.

       --sasl-ir
              Enable initial response in SASL authentication.  (Added in 7.31.0)

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

       --ssl  (FTP, POP3, IMAP, 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. (Added in 7.20.0)

              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.

       --ssl-reqd
              (FTP, POP3, IMAP, SMTP) Require SSL/TLS for the connection.   Terminates  the  connection  if  the
              server doesn't support SSL/TLS. (Added in 7.20.0)

              This  option was formerly known as --ftp-ssl-reqd (added in 7.15.5). That option name can still be
              used but will be removed in a future version.

       --ssl-allow-beast
              (SSL) 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 work-arounds 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)

       --socks4 <host[:port]>
              Use  the  specified SOCKS4 proxy. If the port number is not specified, it is assumed at port 1080.
              (Added in 7.15.2)

              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.

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

       --socks4a <host[:port]>
              Use  the specified SOCKS4a proxy. If the port number is not specified, it is assumed at port 1080.
              (Added in 7.18.0)

              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.

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

       --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. (Added in 7.18.0)

              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.

              If  this  option  is  used  several  times, the last one will be used. (This option was previously
              wrongly documented and used as --socks without the number appended.)

       --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.

              If this option is used several times, the last one will  be  used.  (This  option  was  previously
              wrongly documented and used as --socks without the number appended.)

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

       --socks5-gssapi-service <servicename>
              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-nec
              As part of the gssapi 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).

       --stderr <file>
              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.

       -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.

       -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 for each URL on the command line. Each -T +  URL  pair  specifies  what  to
              upload and to where. curl also supports "globbing" of the -T 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 -T "{file1,file2}" http://www.uploadtothissite.com

              or even

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

       --tcp-nodelay
              Turn  on  the  TCP_NODELAY  option.  See  the  curl_easy_setopt(3) man page for details about this
              option. (Added in 7.11.2)

       --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)

       --tlsauthtype <authtype>
              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 <password>
              Set  password  for  use  with the TLS authentication method specified with --tlsauthtype. Requires
              that --tlsuser also be set.  (Added in 7.21.4)

       --tlsuser <user>
              Set username for use with the TLS authentication method  specified  with  --tlsauthtype.  Requires
              that --tlspassword also be set.  (Added in 7.21.4)

       --tlsv1.0
              (SSL)  Forces  curl  to  use TLS version 1.0 when negotiating with a remote TLS server.  (Added in
              7.34.0)

       --tlsv1.1
              (SSL) Forces curl to use TLS version 1.1 when negotiating with a remote  TLS  server.   (Added  in
              7.34.0)

       --tlsv1.2
              (SSL)  Forces  curl  to  use TLS version 1.2 when negotiating with a remote TLS server.  (Added in
              7.34.0)

       --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 <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 option overrides previous uses of -v, --verbose or --trace-ascii.

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

       --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.

              This option overrides previous uses of -v, --verbose or --trace.

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

       --trace-time
              Prepends a time stamp to each trace or verbose line that curl displays.  (Added in 7.14.0)

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

              If  you  simply  specify  the user name, with or without the login options, curl will prompt for a
              password.

              If you use an SSPI-enabled curl binary and perform NTLM authentication,  you  can  force  curl  to
              select  the  user name and password from your environment by simply specifying a single colon with
              this option: "-u :" or by specfying the login options on their own, for example "-u ;auth=NTLM".

              You can use the optional login options part to specify protocol specific options that may be  used
              during  authentication.  At  present only IMAP, POP3 and SMTP support login options as part of the
              user login information. For more information about the login options please see RFC 2384, RFC 5092
              and IETF draft draft-earhart-url-smtp-00.txt (Added in 7.31.0).

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

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

              If  you  use an SSPI-enabled curl binary and do NTLM authentication, you can force curl to pick up
              the user name and password from your environment by simply specifying a  single  colon  with  this
              option: "-U :".

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

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

              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.

       -v, --verbose
              Makes  the  fetching more verbose/talkative. Mostly useful for debugging. 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.

              Note  that  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.

              This option overrides previous uses of --trace-ascii or --trace.

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

       -w, --write-out <format>
              Defines  what  to  display  on  stdout after a completed and successful operation. The format is a
              string that may contain plain text mixed with any number of variables. The string can be specified
              as  "string",  to  get  read from a particular file you specify it "@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 --remote-name or --output option. It's most useful
                             in combination with the --remote-header-name option. (Added in 7.25.1)

              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)

              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)

              redirect_url   When an HTTP request was made without -L to follow redirects,  this  variable  will
                             show the actual URL a redirect would take you 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)

              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  include  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. The time will be
                             displayed with millisecond resolution.

              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.

       -x, --proxy <[protocol://][user:password@]proxyhost[:port]>
              Use the specified proxy.

              The  proxy  string  can  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, http:// and all others will be treated as HTTP proxies.
              (The protocol support was added in curl 7.21.7)

              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.

       -X, --request <command>
              (HTTP)  Specifies  a  custom  request  method to use when communicating with the HTTP server.  The
              specified request 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.

              (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 insead 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.

       --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.

       -y, --speed-time <time>
              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.

              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.

       -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 and is 30 if not set.

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

       -z, --time-cond <date expression>|<file>
              (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.

       -h, --help
              Usage help.

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

       -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    HTTPS and FTPS are supported.

              libz   Automatic decompression of compressed files over HTTP is supported.

              NTLM   NTLM authentication is supported.

              GSS-Negotiate
                     Negotiate authentication and krb5 for FTP 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.

              SPNEGO SPNEGO Negotiate authentication is supported.

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

              IDN    This curl supports IDN - international domain names.

              SSPI   SSPI is supported. If you use NTLM and set a blank user name, curl will  authenticate  with
                     your current user and password.

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

              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).

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 --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.

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:

       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      FTP 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.

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

       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.

       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     FTP 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

       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

       http://curl.haxx.se

FTP

       ftp://ftp.sunet.se/pub/www/utilities/curl/

SEE ALSO

       ftp(1), wget(1)