nghttp2/src/xsi_strerror.c

/*
 * nghttp2 - HTTP/2 C Library
 *
 * Copyright (c) 2016 Tatsuhiro Tsujikawa
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#include "xsi_strerror.h"

/* Make sure that we get XSI-compliant version of strerror_r */
#ifdef _POSIX_C_SOURCE
#  undef _POSIX_C_SOURCE
#endif /* _POSIX_C_SOURCE */

#ifdef _GNU_SOURCE
#  undef _GNU_SOURCE
#endif /* _GNU_SOURCE */

#include <string.h>

char *xsi_strerror(int errnum, char *buf, size_t buflen) {
  int rv;

  rv = strerror_r(errnum, buf, buflen);

  if (rv != 0) {
    if (buflen > 0) {
      buf[0] = '\0';
    }
  }

  return buf;
}