curl/docs/libcurl/opts/CURLOPT_ERRORBUFFER.3

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.TH CURLOPT_ERRORBUFFER 3 "17 Jun 2014" "libcurl 7.37.0" "curl_easy_setopt options"
.SH NAME
CURLOPT_ERRORBUFFER \- set error buffer for error messages
.SH SYNOPSIS
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ERRORBUFFER, char *buf);
.SH DESCRIPTION
Pass a char * to a buffer that the libcurl may store human readable error
messages in 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 very 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.

Consider \fICURLOPT_VERBOSE(3)\fP and \fICURLOPT_DEBUGFUNCTION(3)\fP to better
debug and trace why errors happen.

If the library does not return an error, the buffer may not have been
touched. Do not rely on the contents in those cases.
.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, "http://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) "