Tribblix: manual page: CURLOPT

CURLOPT_CUSTOMREQUEST(3) Introduction to Library Functions

NAME

CURLOPT_CUSTOMREQUEST - custom request method

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CUSTOMREQUEST, char *method);

DESCRIPTION

Pass a pointer to a null-terminated string as parameter.

When changing the request method by setting CURLOPT_CUSTOMREQUEST(3),
you do not actually change how libcurl behaves or acts: you only
change the actual string sent in the request.

libcurl passes on the verbatim string in its request without any
filter or other safe guards. That includes white space and control
characters.

The application does not have to keep the string around after setting
this option.

Using this option multiple times makes the last set string override
the previous ones. Restore to the internal default by setting this to
NULL.

This option can be used to specify the request:

HTTP Instead of GET or HEAD when performing HTTP based requests.
This is particularly useful, for example, for performing an
HTTP DELETE request.

For example:

When you tell libcurl to do a HEAD request, but then specify a
GET though a custom request libcurl still acts as if it sent a
HEAD. To switch to a proper HEAD use CURLOPT_NOBODY(3), to
switch to a proper POST use CURLOPT_POST(3) or
CURLOPT_POSTFIELDS(3) and to switch to a proper GET use
CURLOPT_HTTPGET(3).

Many people have wrongly used this option to replace the
entire request with their own, including multiple headers and
POST contents. While that might work in many cases, it might
cause libcurl to send invalid requests and it could possibly
confuse the remote server badly. Use CURLOPT_POST(3) and
CURLOPT_POSTFIELDS(3) to set POST data. Use
CURLOPT_HTTPHEADER(3) to replace or extend the set of headers
sent by libcurl. Use CURLOPT_HTTP_VERSION(3) to change HTTP
version.

FTP Instead of LIST and NLST when performing FTP directory
listings.

IMAP Instead of LIST when issuing IMAP based requests.

POP3 Instead of LIST and RETR when issuing POP3 based requests.

For example:

When you tell libcurl to use a custom request it behaves like
a LIST or RETR command was sent where it expects data to be
returned by the server. As such CURLOPT_NOBODY(3) should be
used when specifying commands such as DELE and NOOP for
example.

SMTP Instead of a HELP or VRFY when issuing SMTP based requests.

For example:

Normally a multi line response is returned which can be used,
in conjunction with CURLOPT_MAIL_RCPT(3), to specify an EXPN
request. If the CURLOPT_NOBODY(3) option is specified then the
request can be used to issue NOOP and RSET commands.

DEFAULT

NULL

PROTOCOLS

This functionality affects ftp, http, imap, pop3 and smtp

EXAMPLE

int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
CURLcode res;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");

/* DELETE the given path */
curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "DELETE");

res = curl_easy_perform(curl);

curl_easy_cleanup(curl);
}
}

AVAILABILITY

Added in curl 7.1

RETURN VALUE

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error
occurred, see libcurl-errors(3).