.\" ************************************************************************** .\" * _ _ ____ _ .\" * Project ___| | | | _ \| | .\" * / __| | | | |_) | | .\" * | (__| |_| | _ <| |___ .\" * \___|\___/|_| \_\_____| .\" * .\" * Copyright (C) 1998 - 2021, Daniel Stenberg, , et al. .\" * .\" * This software is licensed as described in the file COPYING, which .\" * you should have received as part of this distribution. The terms .\" * are also available at https://curl.se/docs/copyright.html. .\" * .\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell .\" * copies of the Software, and permit persons to whom the Software is .\" * furnished to do so, under the terms of the COPYING file. .\" * .\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY .\" * KIND, either express or implied. .\" * .\" ************************************************************************** .\" .TH CURLOPT_ERRORBUFFER 3 "17 Jun 2014" "libcurl 7.37.0" "curl_easy_setopt options" .SH NAME CURLOPT_ERRORBUFFER \- error buffer for error messages .SH SYNOPSIS .nf #include CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ERRORBUFFER, char *buf); .fi .SH DESCRIPTION Pass a char * to a buffer that libcurl \fBmay\fP store human readable error messages on failures or problems. This may be more helpful than just the return code from \fIcurl_easy_perform(3)\fP and related functions. The buffer \fBmust be at least CURL_ERROR_SIZE bytes big\fP. You must keep the associated buffer available until libcurl no longer needs it. Failing to do so will cause odd behavior or even crashes. libcurl will need it until you call \fIcurl_easy_cleanup(3)\fP or you set the same option again to use a different pointer. Do not rely on the contents of the buffer unless an error code was returned. Since 7.60.0 libcurl will initialize the contents of the error buffer to an empty string before performing the transfer. For earlier versions if an error code was returned but there was no error detail then the buffer is untouched. Consider \fICURLOPT_VERBOSE(3)\fP and \fICURLOPT_DEBUGFUNCTION(3)\fP to better debug and trace why errors happen. .SH DEFAULT NULL .SH PROTOCOLS All .SH EXAMPLE .nf curl = curl_easy_init(); if(curl) { CURLcode res; char errbuf[CURL_ERROR_SIZE]; curl_easy_setopt(curl, CURLOPT_URL, "https://example.com"); /* provide a buffer to store errors in */ curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errbuf); /* set the error buffer as empty before performing a request */ errbuf[0] = 0; /* perform the request */ res = curl_easy_perform(curl); /* if the request did not complete correctly, show the error information. if no detailed error information was written to errbuf show the more generic information from curl_easy_strerror instead. */ if(res != CURLE_OK) { size_t len = strlen(errbuf); fprintf(stderr, "\\nlibcurl: (%d) ", res); if(len) fprintf(stderr, "%s%s", errbuf, ((errbuf[len - 1] != '\\n') ? "\\n" : "")); else fprintf(stderr, "%s\\n", curl_easy_strerror(res)); } } .fi .SH AVAILABILITY Always .SH RETURN VALUE Returns CURLE_OK .SH "SEE ALSO" .BR CURLOPT_DEBUGFUNCTION "(3), " CURLOPT_VERBOSE "(3), " .BR curl_easy_strerror "(3), " curl_multi_strerror "(3), " .BR curl_share_strerror "(3), " curl_url_strerror "(3)"