curl(1) - phpMan

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
(HTTP, HTTPS, FTP, FTPS, SCP, SFTP, TFTP, DICT, TELNET, LDAP or FILE). The command is
designed to work without user interaction.

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

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

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

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

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

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

ftp://ftp.numericals.com/file[1-100].txt
ftp://ftp.numericals.com/file[001-100].txt (with leading zeros)
ftp://ftp.letters.com/file[a-z].txt

No nesting of the sequences is supported at the moment, 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 sequen-
tial manner in the specified order.

Since curl 7.15.1 you can also specify step counter for the ranges, so that you can 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 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 amount of trans-
ferred data, transfer speeds and estimated time left etc.

However, since curl displays data to the terminal by default, 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 is not spitting out any response
data to the terminal.

If you prefer a progress "bar" instead of the regular meter, -# is your friend.

OPTIONS
-a/--append
(FTP) When used in an FTP 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.

If this option is used twice, the second one will disable append mode again.

-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 it supports. 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.

If this option is used several times, the following occurrences make no difference.

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

If no '=' letter 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.

If this option is used twice, the second one will disable ASCII usage.

--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 and --negoti-
ate).

If this option is used several times, the following occurrences make no difference.

--ciphers <list of ciphers>
(SSL) Specifies which ciphers to use in the connection. The list of ciphers must be
using valid ciphers. Read up on SSL cipher list details on this URL:
http://www.openssl.org/docs/apps/ciphers.html

NSS ciphers are done differently than OpenSSL and GnuTLS. The full list of NSS
ciphers is in the NSSCipherSuite entry at this URL: http://directory.fedora.red-
hat.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 return the uncompressed document. If this option is used and the server sends
an unsupported encoding, Curl will report an error.

If this option is used several times, each occurrence will toggle it on/off.

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

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

-c/--cookie-jar <file name>
Specify to which file you want curl to write all cookies after a completed opera-
tion. 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.

NOTE 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 counted 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.

--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).

If this option is used several times, the following occurrences make no difference.

-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 con-
tent-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 &-letter. Thus, using
'-d name=daniel -d skill=lousy' would generate a post chunk that looks like
'name=daniel&skill=lousy'.

If you start the data with the letter @, the rest should be a file name to read the
data from, or - if you want curl to read the data from stdin. The contents of the
file must already be url-encoded. Multiple files can also be specified. Posting
data from a file named 'foobar' would thus be done with --data @foobar.

--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 separa-
tor 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 @ letters, 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 =
letter 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.

--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, may not work on all servers but enable
more functionality in a better way than the traditional PORT command.

If this option is used several times, each occurrence will toggle this on/off.

--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.

If this option is used several times, each occurrence will toggle this on/off.

-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 invoke
by using the -b/--cookie option! The -c/--cookie-jar option is however a better way
to store cookies.

When used on 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.

-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.

--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 easier allow extraction of useful information after having run curl.

If this option is used several times, each occurrence will toggle this on/off.

--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.

-E/--cert <certificate[:password]>
(SSL) Tells curl to use the specified certificate file when getting a file with
HTTPS or FTPS. The certificate must be in PEM format. If the optional password
isn't specified, it will be queried for on the terminal. Note that this option
assumes a "certificate" file that is the private key and the private certificate
concatenated! See --cert and --key to specify them independently.

If curl is built against the NSS SSL library then this option tells curl the nick-
name of the certificate to use within the NSS database defined by the environment
variable SSL_DIR (or by default /etc/pki/nssdb). If the NSS PEM PKCS#11 module
(libnsspem.so) is available then PEM files may be loaded.

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

--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 that is set, and
uses the given path as a path to a CA cert bundle. This option overrides that vari-
able.

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 nick-
name of the CA certificate to use within the NSS database defined by the environ-
ment variable SSL_DIR (or by default /etc/pki/nssdb). If the NSS PEM PKCS#11 mod-
ule (libnsspem.so) is available then PEM files may be loaded.

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

--capath <CA certificate directory>
(SSL) Tells curl to use the specified certificate directory to verify the peer. The
certificates must be in PEM format, and the directory must have been processed
using the c_rehash utility supplied with openssl. Using --capath can allow curl to
make SSL-connections much more efficiently than using --cacert if the --cacert file
contains many CA certificates.

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

-f/--fail
(HTTP) Fail silently (no output at all) on server errors. This is mostly done like
this 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).

If this option is used twice, the second will again disable silent failure.

--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-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.

If this option is used twice, the second will again disable directory creation.

--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 RFC1738 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 PASV when transferring. PASV is the internal default behavior, but using
this option can be used to override a previous --ftp-port option. (Added in 7.11.0)

If this option is used several times, the following occurrences make no difference.

--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-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.

If this option is used twice, the second will again use the server's suggested
address.

--ftp-ssl
(FTP) Try to use SSL/TLS for the FTP connection. Reverts to a non-secure connec-
tion if the server doesn't support SSL/TLS. See also --ftp-ssl-control and --ftp-
ssl-reqd for different levels of encryption required. (Added in 7.11.0)

If this option is used twice, the second will again disable this.

--ftp-ssl-control
(FTP) Require SSL/TLS for the ftp login, clear for transfer. Allows secure authen-
tication, but non-encrypted data transfers for efficiency. Fails the transfer if
the server doesn't support SSL/TLS. (Added in 7.16.0)

If this option is used twice, the second will again disable this.

--ftp-ssl-reqd
(FTP) Require SSL/TLS for the FTP connection. Terminates the connection if the
server doesn't support SSL/TLS. (Added in 7.15.5)

If this option is used twice, the second will again disable this.

--ftp-ssl-ccc
(FTP) Use CCC (Clear Command Channel) Shuts down the SSL/TLS layer after authenti-
cating. 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)

If this option is used twice, the second will again disable this.

--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)

-F/--form <name=content>
(HTTP) This lets curl emulate a filled in form in which a user has pressed the sub-
mit button. This causes curl to POST data using the Content-Type multipart/form-
data according to RFC1867. 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 letter <. 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 the file's content from stdin instead of a file, use - where the file name
should've been. This goes for both @ and < constructs.

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

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

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

You can also explicitly change the name field of an 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.

--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 pos-
sibility 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 inter-
preted 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.

-h/--help
Usage help.

-H/--header <header>
(HTTP) Extra header to use when getting a web page. You may specify any number of
extra headers. Note that if you should add a custom header that has the same name
as one of the internal ones curl would use, your externally set header will be used
instead of the internal one. This allows you to make even trickier stuff than curl
would normally do. You should not replace internally set headers without knowing
perfectly well what you're doing. Remove an internal header by giving a replacement
without content on the right side of the colon, as in: -H "Host:".

curl will make sure that each header you add/replace get 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
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...

If this option is used twice, the second will again disable header include.

--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.

-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.

If this option is used twice, the second will again disable header only.

-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.

If this option is used several times, each occurrence will toggle this on/off.

-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 cer-
tificate bundle installed by default. This makes all connections considered "inse-
cure" to fail unless -k/--insecure is used.

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

If this option is used twice, the second time will again disable it.

--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 that the library was built with kerberos4 or GSSAPI (GSS-Nego-
tiate) support. This is not very common. Use -V/--version to see if your curl sup-
ports it.

If this option is used several times, the last one will be 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 white space, colon, the equals
sign or any combination thereof (however, the preferred separator is the equals
sign). If the parameter is to contain white spaces, the parameter must be enclosed
within quotes. Within double quotes, the following escape sequences are available:
\\, \", \t, \n, \r and \v. A backlash preceding any other letter is ignored. If
the first column of a config line is a '#' character, the rest of the line will be
treated as a comment. Only write one option per physical line in the config file.

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

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

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

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

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

1) curl tries to find the "home dir": It first checks for the CURL_HOME and then
the HOME environment variables. Failing that, it uses getpwuid() on unix-like sys-
tems (which returns the home dir given the current user in your system). On Win-
dows, it then checks for the APPDATA variable, or as a last resort the '%USERPRO-
FILE%0lication Data'.

2) On windows, if there is no _curlrc file in the home dir, it checks for one in
the same dir the executable curl 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.

--libcurl <file>
Append this option to any ordinary curl command line, and you will get a libcurl-
using source code written to the file that does the equivalent operation 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_for-
madd(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 use your entire bandwidth.

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

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

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

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

-l/--list-only
(FTP) When listing an FTP directory, this switch forces a name-only view. Espe-
cially 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.

If this option is used twice, the second will again disable list only.

--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 is 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)

-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.

If this option is used twice, the second will again disable location following.

--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 do a site to which you'll send your authentication
info (which is plaintext in the case of HTTP Basic authentication).

If this option is used twice, the second will again disable location following.

--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.

-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.

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

-n/--netrc
Makes curl scan the .netrc 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 hasn't the right permissions (it should not be
world nor 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

If this option is used twice, the second will again disable netrc usage.

--netrc-optional
Very similar to --netrc, but this option makes the .netrc usage optional and not
mandatory as the --netrc 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 sup-
port for Kerberos5 authentication but may be also used along with another authenti-
cation methods. 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 that the library was built with GSSAPI support. This is not
very common. Use -V/--version to see if your version supports GSS-Negotiate.

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

If this option is used several times, the following occurrences make no difference.

-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.

If this option is used twice, the second will again switch on buffering.

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

If this option is used twice, the second will again enable 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 ever should 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)

If this option is used twice, the second will again switch on use of the session
cache.

--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, reversed
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 that the library was 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 multi-
ple 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 you have number of URLs.

See also the --create-dirs option to create the local directories dynamically.

-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.

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

--pass <phrase>
(SSL/SSH) Pass phrase 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. How-
ever, a server may requires a POST to remain a POST after such a redirection. This
option is meaningful only when using -L/--location (Added in 7.17.1)

--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)

If this option is used twice, the second will again disable the proxy use-any
authentication.

--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.

If this option is used twice, the second will again disable proxy HTTP Basic
authentication.

--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.

If this option is used twice, the second will again disable proxy HTTP Digest.

--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.

If this option is used twice, the second will again disable proxy HTTP Negotiate.
(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.

If this option is used twice, the second will again disable proxy HTTP NTLM.

-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.

If this option is used twice, the second will again disable proxy tunnel.

--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.

-P/--ftp-port <address>
(FTP) Reverses the initiator/listener roles when connecting with ftp. This switch
makes Curl use the PORT command instead of PASV. In practise, PORT tells the server
to connect to the client's specified address and port, while PASV asks the server
for an ip address and port 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 exact IP number

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

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

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

-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 com-
mands are sent BEFORE the transfer is taking place (just after the initial PWD com-
mand in an FTP transfer, to be exact). To make commands take place after a success-
ful transfer, prefix them with a dash '-'. To make commands get sent after libcurl
has changed working directory, just before the transfer command(s), prefix the com-
mand with '+' (this is only supported for FTP). You may specify any number of com-
mands. If the server returns failure for one of the commands, the entire operation
will be aborted. You must send syntactically correct FTP commands as RFC959 defines
to FTP servers, or one of the following commands (with appropriate arguments) to
SFTP servers: chgrp, chmod, chown, ln, mkdir, pwd, rename, rm, rmdir, symlink.

This option can be used multiple times.

--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.

-r/--range <range>
(HTTP/FTP/FILE) Retrieve a byte range (i.e a partial document) from a HTTP/1.1, FTP
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 bytes ranges(*)(H)

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

Only digit characters (0-9) are valid in 'start' and 'stop' of range syntax 'start-stop'.
If a non-digit character is given in the range, the server's response will be indeter-
minable, depending on different 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 range downloads only support the simple syntax 'start-stop' (optionally with one of
the numbers omitted). It depends on the non-RFC command SIZE.

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

--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)

If this option is used several times, each occurrence toggles this on/off.

-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.

If this option is used twice, the second time disables this again.

--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
5xx 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 between 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 decide 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 per-
forming, 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 decide the amount.

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

If this option is used twice, the second will again disable silent mode.

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

If this option is used twice, the second will again disable show error.

--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 exclu-
sive.

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 exclu-
sive.

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 exclu-
sive.

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 exclu-
sive.

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.)

--stderr <file>
Redirect all writes to stderr to the specified file instead. If the file name is a
plain '-', it is instead written to stdout. This option has no point when you're
using a shell with decent redirecting capabilities.

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

--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)

If this option is used several times, each occurrence toggles this on/off.

-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.

You can specify one -T for each URL on the command line. Each -T + URL pair speci-
fies 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/

--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)

If this option is used several times, each occurrence will toggle it on/off.

-u/--user <user:password>
Specify user 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 specify-
ing 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 user and password to use for proxy authentication.

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 usable for debugging. Lines
starting with '>' means "header data" sent by curl, '<' means "header data"
received by curl that is hidden in normal cases and lines starting with '*' means
additional info provided by curl.

Note that if you only want HTTP headers in the output, -i/--include might be 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.

If this option is used twice, the second will do nothing extra.

-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.

-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 like %{vari-
able_name} and to output a normal % you just write them like %%. You can output a
newline by using \n, a carriage return with \r and a tab space with \t.

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

Available variables are at this point:

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

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

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

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

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

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

time_pretransfer
The time, in seconds, it took from the start until the file transfer
is 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 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 is
just about to be transferred. This includes time_pretransfer and
also the time the server needs 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 down-
load.

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

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)

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

-x/--proxy <proxyhost[:port]>
Use specified HTTP proxy. If the port number is not specified, it is assumed at
port 1080.

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

Note that 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 done with
the -p/--proxytunnel option.

Starting with 7.14.1, the proxy host can be specified the exact same way as the
proxy environment variables, include protocol prefix (http://) and embedded user +
password.

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

-X/--request <command>
(HTTP) Specifies a custom request method to use when communicating with the HTTP
server. The specified request will be used instead of the method otherwise used
(which defaults to GET). Read the HTTP 1.1 specification for details and explana-
tions.

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

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

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

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

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

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

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

-z/--time-cond <date expression>
(HTTP/FTP) 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 speci-
fied date/time.

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

--max-redirs <num>
Set maximum number of redirection-followings allowed. If -L/--location is used,
this option can be used to prevent curl from following redirections "in absurdum".
By default, the limit is set to 50 redirections. Set this option to -1 to make it
limitless.

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

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

-1/--tlsv1
(SSL) Forces curl to use TSL 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.

-#/--progress-bar
Make curl display progress information as a progress bar instead of the default
statistics.

If this option is used twice, the second will again disable the progress bar.

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

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

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

FTP_PROXY [protocol://]<host>[:port]
Sets proxy server to use for FTP.

ALL_PROXY [protocol://]<host>[:port]
Sets 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.

EXIT CODES
There exists 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 malformat. The syntax was not correct.

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 upload-
ing.

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 con-
ditions.

30 FTP PORT failed. The PORT command failed. Not all FTP servers support the PORT com-
mand, 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 TELNET option specified.

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 User, password or similar was not accepted and curl failed to login

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

XX There will appear more error codes 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/