blob: 9a4972568b8d97e078002874c690a2efd0a323e8 [file] [log] [blame]
/* strerror.c --- POSIX compatible system error routine
Copyright (C) 2007-2021 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <>. */
#include <config.h>
/* Specification. */
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "intprops.h"
#include "strerror-override.h"
#include "verify.h"
/* Use the system functions, not the gnulib overrides in this file. */
#undef sprintf
char *
strerror (int n)
#undef strerror
static char buf[STACKBUF_LEN];
size_t len;
/* Cast away const, due to the historical signature of strerror;
callers should not be modifying the string. */
const char *msg = strerror_override (n);
if (msg)
return (char *) msg;
msg = strerror (n);
/* Our strerror_r implementation might use the system's strerror
buffer, so all other clients of strerror have to see the error
copied into a buffer that we manage. This is not thread-safe,
even if the system strerror is, but portable programs shouldn't
be using strerror if they care about thread-safety. */
if (!msg || !*msg)
static char const fmt[] = "Unknown error %d";
verify (sizeof buf >= sizeof (fmt) + INT_STRLEN_BOUND (n));
sprintf (buf, fmt, n);
errno = EINVAL;
return buf;
/* Fix STACKBUF_LEN if this ever aborts. */
len = strlen (msg);
if (sizeof buf <= len)
abort ();
memcpy (buf, msg, len + 1);
return buf;