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curl(1)                           Curl Manual                          curl(1)



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 con-
       nections, 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 as a simple progress bar instead of the standard, more informational,  meter.

       -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-capa-
              ble), 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-capa-
              ble), 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 overwrit-
              ing  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 NSSCi-
              pherSuite 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  uncom-
              pressed 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  con-
              nection  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  gener-
              ate 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. Multi-
              ple  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=urlen-
                     coded-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 nor-
              mally always first attempt to use EPSV before PASV, but with this option, it will not try using EPSV.

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

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

       -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 spec-
              ified, 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 inde-
              pendently.

              If curl is built against the NSS SSL library then this option can tell curl the nickname of the certifi-
              cate  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  ran-
              dom 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 certifi-
              cate 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. Multiple  paths  can  be
              provided  by  separating them with ":" (e.g.  "path1:path2:path3"). The certificates must be in PEM for-
              mat, and if curl is built against OpenSSL, the directory must have been  processed  using  the  c_rehash
              utility  supplied  with  OpenSSL.  Using --capath can allow OpenSSL-powered curl to make SSL-connections
              much more efficiently than using --cacert if the --cacert file contains many CA certificates.

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

       -f, --fail
              (HTTP)  Fail  silently (no output at all) on server errors. This is mostly done to better enable scripts
              etc to better deal with failed attempts. In normal cases when 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 < con-
              structs.

              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 transac-
              tion. 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  shut-
              down,  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 pref-
              erence 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  know-
              ing  perfectly well what you're doing. Remove an internal header by giving a replacement without content
              on the right side of the colon, as in: -H "Host:". If you send the custom header with no-value then  its
              header must be terminated with a semicolon, such as -H "X-Custom-Header;" to send "X-Custom-Header:".

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

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

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

       --hostpubmd5 <md5>
              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  "ses-
              sion 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 whites-
              pace, 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 pre-
              ceding 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 writ-
              ten 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. Exam-
              ples: 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 num-
              bers  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  authentica-
              tion).

       -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  redirec-
              tions. 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  authentica-
              tion. 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  buffer-
              ing.

       --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  actu-
              ally 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.  Dis-
       able 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  modi-
              fiers. 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 poten-
              tially 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 proto-
              cols 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 CON-
              NECT 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  syntacti-
              cally  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.  Fol-
              lowing 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  speci-
                     fied 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. Con-
              sider 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). Tran-
              sient 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.

              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 dou-
              bled 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) trans-
                             fer. 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 calcu-
                             late 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 sec-
                             ond.

              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 veri-
                             fication 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 environ-
              ment 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.


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


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

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

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

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

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

       -z, --time-cond <date expression>
              (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)



Curl 7.21.6                      14 April 2009                         curl(1)