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curl(1) | Curl Manual | curl(1) |
NAME¶
curl - transfer a URLSYNOPSIS¶
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.URL¶
The URL syntax is protocol-dependent. You'll find a detailed description in RFC 3986.http://site.{one,two,three}.com
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
http://any.org/archive[1996-1999]/vol[1-4]/part{a,b,c}.html
http://www.numericals.com/file[1-100:10].txt
http://www.letters.com/file[a-z:2].txt
PROGRESS METER¶
curl normally displays a progress meter during operations, indicating the amount of transferred data, transfer speeds and estimated time left, etc.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-capable), this option tells libcurl to resolve names to IPv4 addresses only.
- -6, --ipv6
- If libcurl is capable of resolving an address to multiple IP versions (which it is if it is IPv6-capable), this option tells libcurl to resolve names to IPv6 addresses only. default statistics.
- -a, --append
- (FTP/SFTP) When used in an upload, this will tell curl to append to the target file instead of overwriting it. If the file doesn't exist, it will be created. Note that this flag is ignored by some SSH servers (including OpenSSH).
- -A, --user-agent <agent string>
- (HTTP) Specify the User-Agent string to send to the HTTP
server. Some badly done CGIs fail if this field isn't set to
"Mozilla/4.0". To encode blanks in the string, surround the
string with single quote marks. This can also be set with the -H,
--header option of course.
- --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.
- -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".
- -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.
- -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.
- --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
- --compressed
- (HTTP) Request a compressed response using one of the algorithms libcurl supports, and save the uncompressed document. If this option is used and the server sends an unsupported encoding, curl will report an error.
- --connect-timeout <seconds>
- Maximum time in seconds that you allow the connection to
the server to take. This only limits the connection phase, once curl has
connected this option is of no more use. See also the -m,
--max-time option.
- --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.
- --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.
- -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, --dump-header <file>
- Write the protocol headers to the specified file.
- --data-binary <data>
- (HTTP) This posts data exactly as specified with no extra
processing whatsoever.
- --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)
- content
- This will make curl URL-encode the content and pass that on. Just be careful so that the content doesn't contain any = or @ symbols, as that will then make the syntax match one of the other cases below!
- =content
- This will make curl URL-encode the content and pass that on. The preceding = symbol is not included in the data.
- name=content
- This will make curl URL-encode the content part and pass that on. Note that the name part is expected to be URL-encoded already.
- @filename
- This will make curl load data from the given file (including any newlines), URL-encode that data and pass it on in the POST.
- name@filename
- This will make curl load data from the given file (including any newlines), URL-encode that data and pass it on in the POST. The name part gets an equal sign appended, resulting in name=urlencoded-file-content. Note that the name is expected to be URL-encoded already.
- --delegation LEVEL
- Set LEVEL to tell the server what it is allowed to delegate when it comes to user credentials. Used with GSS/kerberos.
- none
- Don't allow any delegation.
- policy
- Delegates if and only if the OK-AS-DELEGATE flag is set in the Kerberos service ticket, which is a matter of realm policy.
- always
- Unconditionally allow the server to delegate.
- --digest
- (HTTP) Enables HTTP Digest authentication. This is a
authentication that prevents the password from being sent over the wire in
clear text. Use this in combination with the normal -u, --user
option to set user name and password. See also --ntlm,
--negotiate and --anyauth for related options.
- --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.
- --disable-epsv
- (FTP) Tell curl to disable the use of the EPSV command when
doing passive FTP transfers. Curl will normally always first attempt to
use EPSV before PASV, but with this option, it will not try using EPSV.
- -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.
- -E, --cert <certificate[:password]>
- (SSL) Tells curl to use the specified client certificate
file when getting a file with HTTPS, FTPS or another SSL-based protocol.
The certificate must be in PEM format. If the optional password isn't
specified, it will be queried for on the terminal. Note that this option
assumes a "certificate" file that is the private key and the
private certificate concatenated! See --cert and --key to
specify them independently.
- --engine <name>
- Select the OpenSSL crypto engine to use for cipher operations. Use --engine list to print a list of build-time supported engines. Note that not all (or none) of the engines may be available at run-time.
- --environment
- (RISC OS ONLY) Sets a range of environment variables, using the names the -w option supports, to allow easier extraction of useful information after having run curl.
- --egd-file <file>
- (SSL) Specify the path name to the Entropy Gathering Daemon socket. The socket is used to seed the random engine for SSL connections. See also the --random-file option.
- --cert-type <type>
- (SSL) Tells curl what certificate type the provided
certificate is in. PEM, DER and ENG are recognized types. If not
specified, PEM is assumed.
- --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.
- --capath <CA certificate directory>
- (SSL) Tells curl to use the specified certificate directory
to verify the peer. Multiple paths can be provided by separating them with
":" (e.g. "path1:path2:path3"). The certificates must
be in PEM format, and if curl is built against OpenSSL, the directory must
have been processed using the c_rehash utility supplied with OpenSSL.
Using --capath can allow OpenSSL-powered curl to make
SSL-connections much more efficiently than using --cacert if the
--cacert file contains many CA certificates.
- -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.
- -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.
- --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)
- --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'.
- --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)
- --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)
- --ftp-pret
- (FTP) Tell curl to send a PRET command before PASV (and EPSV). Certain FTP servers, mainly drftpd, require this non-standard command for directory listings as well as up and downloads in PASV mode. (Added in 7.20.x)
- --ftp-ssl-ccc
- (FTP) Use CCC (Clear Command Channel) Shuts down the SSL/TLS layer after authenticating. The rest of the control channel communication will be unencrypted. This allows NAT routers to follow the FTP transaction. The default mode is passive. See --ftp-ssl-ccc-mode for other modes. (Added in 7.16.1)
- --ftp-ssl-ccc-mode [active/passive]
- (FTP) Use CCC (Clear Command Channel) Sets the CCC mode. The passive mode will not initiate the shutdown, but instead wait for the server to do it, and will not reply to the shutdown from the server. The active mode initiates the shutdown and waits for a reply from the server. (Added in 7.16.2)
- --ftp-ssl-control
- (FTP) Require SSL/TLS for the FTP login, clear for transfer. Allows secure authentication, but non-encrypted data transfers for efficiency. Fails the transfer if the server doesn't support SSL/TLS. (Added in 7.16.0) that can still be used but will be removed in a future version.
- --form-string <name=string>
- (HTTP) Similar to --form except that the value string for the named parameter is used literally. Leading '@' and '<' characters, and the ';type=' string in the value have no special meaning. Use this in preference to --form if there's any possibility that the string value may accidentally trigger the '@' or '<' features of --form.
- -g, --globoff
- This option switches off the "URL globbing parser". When you set this option, you can specify URLs that contain the letters {}[] without having them being interpreted by curl itself. Note that these letters are not normal legal URL contents but they should be encoded according to the URI standard.
- -G, --get
- When used, this option will make all data specified with
-d, --data or --data-binary to be used in a HTTP GET request
instead of the POST request that otherwise would be used. The data will be
appended to the URL with a '?' separator.
- -H, --header <header>
- (HTTP) Extra header to use when getting a web page. You may
specify any number of extra headers. Note that if you should add a custom
header that has the same name as one of the internal ones curl would use,
your externally set header will be used instead of the internal one. This
allows you to make even trickier stuff than curl would normally do. You
should not replace internally set headers without knowing perfectly well
what you're doing. Remove an internal header by giving a replacement
without content on the right side of the colon, as in: -H
"Host:". If you send the custom header with no-value then its
header must be terminated with a semicolon, such as -H
"X-Custom-Header;" to send "X-Custom-Header:".
- --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/
- -j, --junk-session-cookies
- (HTTP) When curl is told to read cookies from a given file, this option will make it discard all "session cookies". This will basically have the same effect as if a new session is started. Typical browsers always discard session cookies when they're closed down.
- -J, --remote-header-name
- (HTTP) This option tells the -O, --remote-name option to use the server-specified Content-Disposition filename instead of extracting a filename from the URL.
- -k, --insecure
- (SSL) This option explicitly allows curl to perform
"insecure" SSL connections and transfers. All SSL connections
are attempted to be made secure by using the CA certificate bundle
installed by default. This makes all connections considered
"insecure" fail unless -k, --insecure is used.
- -K, --config <config file>
- Specify which config file to read curl arguments from. The
config file is a text file in which command line arguments can be written
which then will be used as if they were written on the actual command
line. Options and their parameters must be specified on the same config
file line, separated by whitespace, colon, the equals sign or any
combination thereof (however, the preferred separator is the equals sign).
If the parameter is to contain whitespace, the parameter must be enclosed
within quotes. Within double quotes, the following escape sequences are
available: \\, \", \t, \n, \r and \v. A backslash preceding any other
letter is ignored. If the first column of a config line is a '#'
character, the rest of the line will be treated as a comment. Only write
one option per physical line in the config file.
# --- 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 ---
- --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)
- --key <key>
- (SSL/SSH) Private key file name. Allows you to provide your
private key in this separate file.
- --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.
- --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.
- -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.
- -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.
- --libcurl <file>
- Append this option to any ordinary curl command line, and
you will get a libcurl-using C source code written to the file that does
the equivalent of what your command-line operation does!
- --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.
- --local-port <num>[-num]
- Set a preferred number or range of local port numbers to use for the connection(s). Note that port numbers by nature are a scarce resource that will be busy at times so setting this range to something too narrow might cause unnecessary connection setup failures. (Added in 7.15.2)
- --location-trusted
- (HTTP/HTTPS) Like -L, --location, but will allow sending the name + password to all hosts that the site may redirect to. This may or may not introduce a security breach if the site redirects you to a site to which you'll send your authentication info (which is plaintext in the case of HTTP Basic authentication).
- -m, --max-time <seconds>
- Maximum time in seconds that you allow the whole operation
to take. This is useful for preventing your batch jobs from hanging for
hours due to slow networks or links going down. See also the
--connect-timeout option.
- --mail-auth <address>
- (SMTP) Specify a single address. This will be used to
specify the authentication address (identity) of a submitted message that
is being relayed to another server.
- --mail-from <address>
- (SMTP) Specify a single address that the given mail should
get sent from.
- --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.
- --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.
- --max-redirs <num>
- Set maximum number of redirection-followings allowed. If
-L, --location is used, this option can be used to prevent curl
from following redirections "in absurdum". By default, the limit
is set to 50 redirections. Set this option to -1 to make it limitless.
- -n, --netrc
- Makes curl scan the .netrc (_netrc on
Windows) file in the user's home directory for login name and password.
This is typically used for FTP on UNIX. If used with HTTP, curl will
enable user authentication. See netrc(4) or ftp(1) for
details on the file format. Curl will not complain if that file doesn't
have the right permissions (it should not be either world- or
group-readable). The environment variable "HOME" is used to find
the home directory.
- -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.
- --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)
- --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.
- --no-keepalive
- Disables the use of keepalive messages on the TCP
connection, as by default curl enables them.
- --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)
- --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.
- -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"
curl http://{site,host}.host[1-5].com -o "#1_#2"
- -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.)
- -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
- --pass <phrase>
- (SSL/SSH) Passphrase for the private key
- --post301
- Tells curl to respect RFC 2616/10.3.2 and not convert POST requests into GET requests when following a 301 redirection. The non-RFC behaviour is ubiquitous in web browsers, so curl does the conversion by default to maintain consistency. However, a server may require a POST to remain a POST after such a redirection. This option is meaningful only when using -L, --location (Added in 7.17.1)
- --post302
- Tells curl to respect RFC 2616/10.3.2 and not convert POST requests into GET requests when following a 302 redirection. The non-RFC behaviour is ubiquitous in web browsers, so curl does the conversion by default to maintain consistency. However, a server may require a POST to remain a POST after such a redirection. This option is meaningful only when using -L, --location (Added in 7.19.1)
- --proto <protocols>
- Tells curl to use the listed protocols for its initial retrieval. Protocols are evaluated left to right, are comma separated, and are each a protocol name or 'all', optionally prefixed by zero or more modifiers. Available modifiers are:
- +
- Permit this protocol in addition to protocols already permitted (this is the default if no modifier is used).
- -
- Deny this protocol, removing it from the list of protocols already permitted.
- =
- Permit only this protocol (ignoring the list already permitted), though subject to later modification by subsequent entries in the comma separated list.
- For example:
- --proto -ftps
- uses the default protocols, but disables ftps
- --proto -all,https,+http
- only enables http and https
- --proto =http,https
- also only enables http and https
- Unknown protocols produce a warning. This allows scripts to
safely rely on being able to disable potentially dangerous protocols,
without relying upon support for that protocol being built into curl to
avoid an error.
- --proto-redir <protocols>
- Tells curl to use the listed protocols after a redirect.
See --proto for how protocols are represented.
- --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.
- --pubkey <key>
- (SSH) Public key file name. Allows you to provide your
public key in this separate file.
- -q
- If used as the first parameter on the command line, the curlrc config file will not be read and used. See the -K, --config for details on the default config file search path.
- -Q, --quote <command>
- (FTP/SFTP) Send an arbitrary command to the remote FTP or
SFTP server. Quote commands are sent BEFORE the transfer takes place (just
after the initial PWD command in an FTP transfer, to be exact). To make
commands take place after a successful transfer, prefix them with a dash
'-'. To make commands be sent after libcurl has changed the working
directory, just before the transfer command(s), prefix the command with a
'+' (this is only supported for FTP). You may specify any number of
commands. If the server returns failure for one of the commands, the
entire operation will be aborted. You must send syntactically correct FTP
commands as RFC 959 defines to FTP servers, or one of the commands listed
below to SFTP servers. This option can be used multiple times. When
speaking to a FTP server, prefix the command with an asterisk (*) to make
libcurl continue even if the command fails as by default curl will stop at
first failure.
- chgrp group file
- The chgrp command sets the group ID of the file named by the file operand to the group ID specified by the group operand. The group operand is a decimal integer group ID.
- chmod mode file
- The chmod command modifies the file mode bits of the specified file. The mode operand is an octal integer mode number.
- chown user file
- The chown command sets the owner of the file named by the file operand to the user ID specified by the user operand. The user operand is a decimal integer user ID.
- ln source_file target_file
- The ln and symlink commands create a symbolic link at the target_file location pointing to the source_file location.
- mkdir directory_name
- The mkdir command creates the directory named by the directory_name operand.
- pwd
- The pwd command returns the absolute pathname of the current working directory.
- rename source target
- The rename command renames the file or directory named by the source operand to the destination path named by the target operand.
- rm file
- The rm command removes the file specified by the file operand.
- rmdir directory
- The rmdir command removes the directory entry specified by the directory operand, provided it is empty.
- symlink source_file target_file
- See ln.
- -r, --range <range>
- (HTTP/FTP/SFTP/FILE) Retrieve a byte range (i.e a partial document) from a HTTP/1.1, FTP or SFTP server or a local FILE. Ranges can be specified in a number of ways.
- 0-499
- specifies the first 500 bytes
- 500-999
- specifies the second 500 bytes
- -500
- specifies the last 500 bytes
- 9500-
- specifies the bytes from offset 9500 and forward
- 0-0,-1
- specifies the first and last byte only(*)(H)
- 500-700,600-799
- specifies 300 bytes from offset 500(H)
- 100-199,500-599
- specifies two separate 100-byte ranges(*)(H)
- -R, --remote-time
- When used, this will make libcurl attempt to figure out the timestamp of the remote file, and if that is available make the local file get that same timestamp.
- --random-file <file>
- (SSL) Specify the path name to file containing what will be considered as random data. The data is used to seed the random engine for SSL connections. See also the --egd-file option.
- --raw
- When used, it disables all internal HTTP decoding of content or transfer encodings and instead makes them passed on unaltered, raw. (Added in 7.16.2)
- --remote-name-all
- This option changes the default action for all given URLs to be dealt with as if -O, --remote-name were used for each one. So if you want to disable that for a specific URL after --remote-name-all has been used, you must use "-o -" or --no-remote-name. (Added in 7.19.0)
- --resolve <host:port:address>
- Provide a custom address for a specific host and port pair.
Using this, you can make the curl requests(s) use a specified address and
prevent the otherwise normally resolved address to be used. Consider it a
sort of /etc/hosts alternative provided on the command line. The port
number should be the number used for the specific protocol the host will
be used for. It means you need several entries if you want to provide
address for the same host but different ports.
- --retry <num>
- If a transient error is returned when curl tries to perform
a transfer, it will retry this number of times before giving up. Setting
the number to 0 makes curl do no retries (which is the default). Transient
error means either: a timeout, an FTP 4xx response code or an HTTP 5xx
response code.
- --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)
- --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)
- -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)
- --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)
- --ssl-allow-beast
- (SSL) This option tells curl to not work around a security flaw in the SSL3 and TLS1.0 protocols known as BEAST. If this option isn't used, the SSL layer may use work-arounds known to cause interoperability problems with some older SSL implementations. WARNING: this option loosens the SSL security, and by using this flag you ask for exactly that. (Added in 7.25.0)
- --socks4 <host[:port]>
- Use the specified SOCKS4 proxy. If the port number is not
specified, it is assumed at port 1080. (Added in 7.15.2)
- --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)
- --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)
- --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.
- --socks5-gssapi-service <servicename>
- The default service name for a socks server is
rcmd/server-fqdn. This option allows you to change it.
- --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.
- -t, --telnet-option <OPT=val>
- Pass options to the telnet protocol. Supported options are:
- -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.
- --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.
- --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.
- --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.
- --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.
- --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.
- -U, --proxy-user <user:password>
- Specify the user name and password to use for proxy
authentication.
- --url <URL>
- Specify a URL to fetch. This option is mostly handy when
you want to specify URL(s) in a config file.
- -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.
- -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 "@-".
- url_effective
- The URL that was fetched last. This is most meaningful if you've told curl to follow location: headers.
- filename_effective
- The ultimate filename that curl writes out to. This is only meaningful if curl is told to write to a file with the --remote-name or --output option. It's most useful in combination with the --remote-header-name option. (Added in 7.25.1)
- http_code
- The numerical response code that was found in the last retrieved HTTP(S) or FTP(s) transfer. In 7.18.2 the alias response_code was added to show the same info.
- http_connect
- The numerical code that was found in the last response (from a proxy) to a curl CONNECT request. (Added in 7.12.4)
- time_total
- The total time, in seconds, that the full operation lasted. The time will be displayed with millisecond resolution.
- time_namelookup
- The time, in seconds, it took from the start until the name resolving was completed.
- time_connect
- The time, in seconds, it took from the start until the TCP connect to the remote host (or proxy) was completed.
- time_appconnect
- The time, in seconds, it took from the start until the SSL/SSH/etc connect/handshake to the remote host was completed. (Added in 7.19.0)
- time_pretransfer
- The time, in seconds, it took from the start until the file transfer was just about to begin. This includes all pre-transfer commands and negotiations that are specific to the particular protocol(s) involved.
- time_redirect
- The time, in seconds, it took for all redirection steps include name lookup, connect, pretransfer and transfer before the final transaction was started. time_redirect shows the complete execution time for multiple redirections. (Added in 7.12.3)
- time_starttransfer
- The time, in seconds, it took from the start until the first byte was just about to be transferred. This includes time_pretransfer and also the time the server needed to calculate the result.
- size_download
- The total amount of bytes that were downloaded.
- size_upload
- The total amount of bytes that were uploaded.
- size_header
- The total amount of bytes of the downloaded headers.
- size_request
- The total amount of bytes that were sent in the HTTP request.
- speed_download
- The average download speed that curl measured for the complete download. Bytes per second.
- speed_upload
- The average upload speed that curl measured for the complete upload. Bytes per second.
- content_type
- The Content-Type of the requested document, if there was any.
- num_connects
- Number of new connects made in the recent transfer. (Added in 7.12.3)
- num_redirects
- Number of redirects that were followed in the request. (Added in 7.12.3)
- redirect_url
- When a HTTP request was made without -L to follow redirects, this variable will show the actual URL a redirect would take you to. (Added in 7.18.2)
- ftp_entry_path
- The initial path libcurl ended up in when logging on to the remote FTP server. (Added in 7.15.4)
- ssl_verify_result
- The result of the SSL peer certificate verification that was requested. 0 means the verification was successful. (Added in 7.19.0)
- -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.
- -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.
- --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.
- -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.
- -z/--time-cond <date expression>|<file>
- (HTTP/FTP) Request a file that has been modified later than
the given time and date, or one that has been modified before that time.
The <date expression> can be all sorts of date strings or if it
doesn't match any internal ones, it is taken as a filename and tries to
get the modification date (mtime) from <file> instead. See the
curl_getdate(3) man pages for date expression details.
- -h, --help
- Usage help.
- -M, --manual
- Manual. Display the huge help text.
- -V, --version
- Displays information about curl and the libcurl version it
uses.
- 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¶
~/.curlrcDefault 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.- 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.- 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.seFTP¶
ftp://ftp.sunet.se/pub/www/utilities/curl/SEE ALSO¶
ftp(1), wget(1)16 February 2012 | Curl 7.25.0 |