Provided by: curl_7.22.0-3ubuntu4_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 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

       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 information as a progress bar instead of the

       -0, --http1.0
              (HTTP) Forces curl to issue its requests  using  HTTP  1.0  instead  of  using  its
              internally preferred: HTTP 1.1.

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

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

       -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 set more than once, the last one will be the one that's 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 set more than once, the last one will be the one that's used.

       -B, --use-ascii
              Enable ASCII transfer when using FTP or LDAP. 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>
              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://directory.fedora.redhat.com/docs/mod_nss.html#Directives

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

       --compressed
              (HTTP)  Request a compressed response using one of the algorithms libcurl 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. 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.  The contents of  the
              file  must  already  be  URL-encoded. Multiple files can also be specified. Posting
              data from a file named 'foobar' would thus be done with --data @foobar.

       -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  a  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.  IP  "--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 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 a authentication 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, the following occurrences make no difference.

       --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 EPRT 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.

       -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 PEM
              format.  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 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 then this option tells curl the
              nickname of the CA 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 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. 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 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
              a  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

              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 twice, the second will override the previous use.

       --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 a 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, the following occurrences make no difference.
              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  or  --data-
              binary  to be used in a 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, the following occurrences make no difference.
              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:".

              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>
              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. This option is only for SCP and SFTP transfers.
              (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 a 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.

       -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, the equals
              sign or any combination thereof (however, the preferred  separator  is  the  equals
              sign).  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/"

              Long  option  names  can optionally be given in the config file without the initial
              double dashes.

              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 multiple times, the last occurrence sets the amount.

       --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.
              Especially  useful  if  you  want to machine-parse the contents of an FTP directory
              since the normal directory view doesn't use a standard look or format.

              This option causes an FTP NLST command to be sent.   Some  FTP  servers  list  only
              files  in  their  response to NLST; they do not include subdirectories and symbolic
              links.

       -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  source  code  written  to  the  file  that  does the equivalent of what your
              command-line operation does!

              NOTE: this does not properly support -F and the sending of multipart formposts,  so
              in   those   cases   the   output  program  will  be  missing  necessary  calls  to
              curl_formadd(3), and possibly more.

              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.  See also the --connect-timeout option.

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

       --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 that the given mail should get sent to. This option
              can be used multiple times to specify many recipients.

              (Added in 7.20.0)

       --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.

       -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, the following occurrences make no difference.

       --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, the following occurrences make no difference.

       -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!

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

       -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
              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
              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)

       --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
              libcurl 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 a FTP server,
              prefix the command with an asterisk (*)  to  make  libcurl  continue  even  if  the
              command fails as by default curl will stop at first failure.

              SFTP  is  a binary protocol. Unlike for FTP, libcurl 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 libcurl 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  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 multiple times, the last occurrence decide the amount.

       --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 multiple times, the last occurrence determines the amount.

       --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 multiple times, the last occurrence determines the amount.

       -s, --silent
              Silent or quiet mode. Don't show progress meter  or  error  messages.   Makes  Curl
              mute.

       -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.

       --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. This option has no point when you're
              using a shell with decent redirecting capabilities.

              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 a
              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)

       --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)

       --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)

       --tr-encoding
              (HTTP) Request a compressed Transfer-Encoding response using one of the  algorithms
              libcurl 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>
              Specify the user name and password to use for server authentication. Overrides  -n,
              --netrc and --netrc-optional.

              If  you  just  give the user name (without entering a colon) curl will prompt for a
              password.

              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.

       -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 at this point are:

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

              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)

              time_total     The total time, in seconds, that the full operation lasted. The time
                             will be displayed with millisecond resolution.

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

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

              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_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.

              size_download  The total amount of bytes that were downloaded.

              size_upload    The total amount of bytes that were uploaded.

              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.

              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.

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

              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 a 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)

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

              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)

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

       -x, --proxy <[protocol://][user@password]proxyhost[:port]>
              Use the specified HTTP proxy. If the port number is not specified, it is assumed at
              port 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 a 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.

              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.

              From 7.21.7, the proxy string may 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.

              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.

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

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

       -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>
              (HTTP/FTP/FILE) 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 tries to get
              the time from a given file name 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.

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 a 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

       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)