1 /* strerror.c --- ANSI C compatible system error routine
2
3 Copyright (C) 1986, 1988, 1989, 1991, 2002, 2003 Free Software
4 Foundation, Inc.
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software Foundation,
18 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
19
20 #ifdef HAVE_CONFIG_H
21 # include <config.h>
22 #endif
23
24 #include <limits.h>
25
26 /* Don't include <stdio.h>, since it may or may not declare
27 sys_errlist and its declarations may collide with ours. Just
28 declare the stuff that we need directly. Standard hosted C89
29 implementations define strerror and they don't need this strerror
30 function, so take some liberties with the standard to cater to
31 ancient or limited freestanding implementations. */
32 int sprintf (char *, char const *, ...);
33 extern int sys_nerr;
34 extern char *sys_errlist[];
35
36 char *
strerror(int n)37 strerror (int n)
38 {
39 static char const fmt[] = "Unknown error (%d)";
40 static char mesg[sizeof fmt + sizeof n * CHAR_BIT / 3];
41
42 if (n < 0 || n >= sys_nerr)
43 {
44 sprintf (mesg, fmt, n);
45 return mesg;
46 }
47 else
48 return sys_errlist[n];
49 }
50