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/* Copyright (C) 1991, 1993, 1994 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
/*
* Manuel Novoa III Dec 2000
*
* Converted to use my new (un)signed long (long) to string routines, which
* are smaller than the previous functions and don't require static buffers.
* Removed dependence on strcat in the process.
*
* Also appended a test routine ( -DSTRERROR_TEST ) to allow a quick check
* on the buffer length when the sys_errorlist is modified.
*/
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <limits.h>
#if (INT_MAX >> 31)
/* We're set up for 32 bit ints */
#error need to check size allocation for static buffer 'retbuf'
#endif
extern char *__ltostr(char *buf, long uval, int base, int uppercase);
static char retbuf[33]; /* 33 is sufficient for 32 bit ints */
static const char unknown_error[] = "Unknown Error: errno"; /* = */
/* Return a string descibing the errno code in ERRNUM.
The storage is good only until the next call to strerror.
Writing to the storage causes undefined behavior. */
char *strerror(int err)
{
char *pos;
if ((err >= 0) && (err < sys_nerr)) {
strcpy(retbuf, sys_errlist[err]);
return retbuf;
}
/* unknown error */
pos = __ltostr(retbuf + sizeof(retbuf) + 1, err, 10, 0)
- sizeof(unknown_error); /* leave space for the '=' */
strcpy(pos, unknown_error);
*(pos + sizeof(unknown_error) - 1) = '=';
return pos;
}
#if STRERROR_TEST
/* quick way to check for sufficient buffer length */
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
int max = 0;
int i, j;
char *p;
for ( i=0 ; i < sys_nerr ; i++ ) {
j = strlen(sys_errlist[i])+1;
if (j > max) max = j;
}
printf("max len = %i\n", j);
p = strerror(INT_MIN);
printf("<%s> %d\n", p, strlen(p)+1);
printf("current buffer length is %d\n", sizeof(retbuf));
return EXIT_SUCCESS;
}
#endif
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