CURLOPT_FAILONERROR(3) Library Functions Manual CURLOPT_FAILONERROR(3)
NAME
CURLOPT_FAILONERROR - request failure on HTTP response >= 400
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FAILONERROR, long fail);
DESCRIPTION
A long parameter set to 1 tells the library to fail the request if the
HTTP code returned is equal to or larger than 400. The default action
would be to return the page normally, ignoring that code.
This method is not fail-safe and there are occasions where non-success-
ful response codes slip through, especially when authentication is in-
volved (response codes 401 and 407).
You might get some amounts of headers transferred before this situation
is detected, like when a "100-continue" is received as a response to a
POST/PUT and a 401 or 407 is received immediately afterwards.
When this option is used and an error is detected, it causes the connec-
tion to get closed and CURLE_HTTP_RETURNED_ERROR is returned.
DEFAULT
0, do not fail on error
PROTOCOLS
This functionality affects http only
EXAMPLE
int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
CURLcode ret;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1L);
ret = curl_easy_perform(curl);
if(ret == CURLE_HTTP_RETURNED_ERROR) {
/* an HTTP response error problem */
}
}
}
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).
SEE ALSO
CURLINFO_RESPONSE_CODE(3), CURLOPT_HTTP200ALIASES(3), CURLOPT_KEEP_SEND-
ING_ON_ERROR(3)
libcurl 2026-07-12 CURLOPT_FAILONERROR(3)
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