freebsd-skq/lib/libc/string/strerror.c
mini 46aac0b82f Fix off-by-one error.
PR:		misc/40104
Submitted by:	Neal Fachan <neal@isilon.com>
MFC after:	3 days
2002-07-03 06:28:04 +00:00

145 lines
4.6 KiB
C

/*
* Copyright (c) 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)strerror.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <stdio.h>
#include <string.h>
#include <errno.h>
int
strerror_r(int errnum, char *strerrbuf, size_t buflen)
{
int len;
if ((errnum >= 0) && (errnum < sys_nerr)) {
len = strlcpy(strerrbuf, (char *)sys_errlist[errnum], buflen);
return ((len < buflen) ? 0 : ERANGE);
}
return (EINVAL);
}
char *
strerror(num)
int num;
{
char *p, *t;
unsigned int uerr;
static char const unknown_prefix[] = "Unknown error: ";
/*
* Define a buffer size big enough to describe a 64-bit
* number in ASCII decimal (19), with optional leading sign
* (+1) and trailing NUL (+1).
*/
# define NUMLEN 21
# define EBUFLEN (sizeof unknown_prefix + NUMLEN)
char tmp[NUMLEN]; /* temporary number */
static char ebuf[EBUFLEN]; /* error message */
if ((num >= 0) && (num < sys_nerr))
return ((char *)sys_errlist[num]);
/*
* Set errno to EINVAL per P1003.1-200x Draft June 14, 2001.
*/
errno = EINVAL;
/*
* Print unknown errno by hand so we don't link to stdio(3).
* This collects the ASCII digits in reverse order.
*/
uerr = (num > 0) ? num : -num;
t = tmp;
do {
*t++ = "0123456789"[uerr % 10];
} while (uerr /= 10);
if (num < 0)
*t++ = '-';
/*
* Copy the "unknown" message and the number into the caller
* supplied buffer, inverting the number string.
*/
strcpy(ebuf, unknown_prefix);
for (p = ebuf + sizeof unknown_prefix - 1; t > tmp; )
*p++ = *--t;
*p = '\0';
return (ebuf);
}
#ifdef STANDALONE_TEST
#include <limits.h>
main()
{
char mybuf[64];
int ret;
errno = 0;
printf("strerror(0) yeilds: %s\n", strerror(0));
printf("strerror(1) yeilds: %s\n", strerror(1));
printf("strerror(47) yeilds: %s\n", strerror(47));
printf("strerror(sys_nerr - 1) yeilds: %s\n", strerror(sys_nerr - 1));
printf("errno = %d\n", errno); errno = 0;
printf("strerror(sys_nerr) yeilds: %s\n", strerror(sys_nerr));
printf("errno = %d\n", errno); errno = 0;
printf("strerror(437) yeilds: %s\n", strerror(437));
printf("errno = %d\n", errno); errno = 0;
printf("strerror(LONG_MAX) yeilds: %s\n", strerror(LONG_MAX));
printf("strerror(LONG_MIN) yeilds: %s\n", strerror(LONG_MIN));
printf("strerror(ULONG_MAX) yeilds: %s\n", strerror(ULONG_MAX));
memset(mybuf, '*', 63); mybuf[63] = '\0';
strerror_r(11, mybuf, 64);
printf("strerror_r(11) yeilds: %s\n", mybuf);
memset(mybuf, '*', 63); mybuf[63] = '\0';
ret = strerror_r(1234, mybuf, 64);
printf("strerror_r(1234) returns %d (%s)\n", ret, mybuf);
memset(mybuf, '*', 63); mybuf[63] = '\0';
ret = strerror_r(1, mybuf, 10);
printf("strerror_r on short buffer returns %d (%s)\n", ret, mybuf);
}
#endif