LXR linux/tools/lib/str_error

   1// SPDX-License-Identifier: GPL-2.0
   2#undef _GNU_SOURCE
   3#include <string.h>
   4#include <stdio.h>
   5#include <linux/string.h>
   6
   7/*
   8 * The tools so far have been using the strerror_r() GNU variant, that returns
   9 * a string, be it the buffer passed or something else.
  10 *
  11 * But that, besides being tricky in cases where we expect that the function
  12 * using strerror_r() returns the error formatted in a provided buffer (we have
  13 * to check if it returned something else and copy that instead), breaks the
  14 * build on systems not using glibc, like Alpine Linux, where musl libc is
  15 * used.
  16 *
  17 * So, introduce yet another wrapper, str_error_r(), that has the GNU
  18 * interface, but uses the portable XSI variant of strerror_r(), so that users
  19 * rest asured that the provided buffer is used and it is what is returned.
  20 */
  21char *str_error_r(int errnum, char *buf, size_t buflen)
  22{
  23        int err = strerror_r(errnum, buf, buflen);
  24        if (err)
  25                snprintf(buf, buflen, "INTERNAL ERROR: strerror_r(%d, [buf], %zd)=%d", errnum, buflen, err);
  26        return buf;
  27}
  28