Tribblix: manual page: CURLOPT

CURLOPT_FOLLOWLOCATION(3) Introduction to Library Functions

NAME

CURLOPT_FOLLOWLOCATION - follow HTTP 3xx redirects

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FOLLOWLOCATION, long enable);

DESCRIPTION

A long parameter set to 1 tells the library to follow any Location:
header redirects that an HTTP server sends in a 30x response. The
Location: header can specify a relative or an absolute URL to follow.

libcurl issues another request for the new URL and follows subsequent
new Location: redirects all the way until no more such headers are
returned or the maximum limit is reached. CURLOPT_MAXREDIRS(3) is
used to limit the number of redirects libcurl follows.

libcurl restricts what protocols it automatically follow redirects
to. The accepted target protocols are set with
CURLOPT_REDIR_PROTOCOLS_STR(3). By default libcurl allows HTTP,
HTTPS, FTP and FTPS on redirects.

When following a redirect, the specific 30x response code also
dictates which request method libcurl uses in the subsequent request:
For 301, 302 and 303 responses libcurl switches method from POST to
GET unless CURLOPT_POSTREDIR(3) instructs libcurl otherwise. All
other redirect response codes make libcurl use the same method again.

For users who think the existing location following is too naive, too
simple or just lacks features, it is easy to instead implement your
own redirect follow logic with the use of curl_easy_getinfo(3)'s
CURLINFO_REDIRECT_URL(3) option instead of using
CURLOPT_FOLLOWLOCATION(3).

By default, libcurl only sends Authentication: or explicitly set
Cookie: headers to the initial host given in the original URL, to
avoid leaking username + password to other sites.
CURLOPT_UNRESTRICTED_AUTH(3) is provided to change that behavior.

Due to the way HTTP works, almost any header can be made to contain
data a client may not want to pass on to other servers than the
initially intended host and for all other headers than the two
mentioned above, there is no protection from this happening when
libcurl is told to follow redirects.

NOTE

Since libcurl changes method or not based on the specific HTTP
response code, setting CURLOPT_CUSTOMREQUEST(3) while following
redirects may change what libcurl would otherwise do and if not that
carefully may even make it misbehave since CURLOPT_CUSTOMREQUEST(3)
overrides the method libcurl would otherwise select internally.

DEFAULT

0, disabled

PROTOCOLS

This functionality affects http only

EXAMPLE

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

/* example.com is redirected, so we tell libcurl to follow redirection */
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);

curl_easy_perform(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).