1 /* 2 * Copyright (c) 1988, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char sccsid[] = "@(#)strerror.c 8.1 (Berkeley) 6/4/93"; 36 #endif /* LIBC_SCCS and not lint */ 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include <stdio.h> 41 #include <string.h> 42 #include <errno.h> 43 44 int 45 strerror_r(int errnum, char *strerrbuf, size_t buflen) 46 { 47 int len; 48 49 if ((errnum > 0) && (errnum < sys_nerr)) { 50 len = strlcpy(strerrbuf, (char *)sys_errlist[errnum], buflen); 51 return ((len <= buflen) ? 0 : ERANGE); 52 } 53 return (EINVAL); 54 } 55 56 char * 57 strerror(num) 58 int num; 59 { 60 char *p, *t; 61 unsigned int uerr; 62 static char const unknown_prefix[] = "Unknown error: "; 63 64 /* 65 * Define a buffer size big enough to describe a 64-bit 66 * number in ASCII decimal (19), with optional leading sign 67 * (+1) and trailing NUL (+1). 68 */ 69 # define NUMLEN 21 70 # define EBUFLEN (sizeof unknown_prefix + NUMLEN) 71 char tmp[NUMLEN]; /* temporary number */ 72 static char ebuf[EBUFLEN]; /* error message */ 73 74 if ((num > 0) && (num < sys_nerr)) 75 return ((char *)sys_errlist[num]); 76 77 /* 78 * Print unknown errno by hand so we don't link to stdio(3). 79 * This collects the ASCII digits in reverse order. 80 */ 81 uerr = (num > 0) ? num : -num; 82 t = tmp; 83 do { 84 *t++ = "0123456789"[uerr % 10]; 85 } while (uerr /= 10); 86 if (num < 0) 87 *t++ = '-'; 88 89 /* 90 * Copy the "unknown" message and the number into the caller 91 * supplied buffer, inverting the number string. 92 */ 93 strcpy(ebuf, unknown_prefix); 94 for (p = ebuf + sizeof unknown_prefix - 1; t >= tmp; ) 95 *p++ = *--t; 96 *p = '\0'; 97 return (ebuf); 98 } 99 100 #ifdef STANDALONE_TEST 101 102 #include <limits.h> 103 104 main() 105 { 106 char mybuf[64]; 107 int ret; 108 109 printf("strerror(47) yeilds: %s\n", strerror(47)); 110 printf("strerror(437) yeilds: %s\n", strerror(437)); 111 printf("strerror(LONG_MAX) yeilds: %s\n", strerror(LONG_MAX)); 112 printf("strerror(LONG_MIN) yeilds: %s\n", strerror(LONG_MIN)); 113 printf("strerror(ULONG_MAX) yeilds: %s\n", strerror(ULONG_MAX)); 114 115 memset(mybuf, '*', 63); mybuf[63] = '\0'; 116 strerror_r(11, mybuf, 64); 117 printf("strerror_r(11) yeilds: %s\n", mybuf); 118 119 memset(mybuf, '*', 63); mybuf[63] = '\0'; 120 ret = strerror_r(1234, mybuf, 64); 121 printf("strerror_r(1234) returns %d (%s)\n", ret, mybuf); 122 123 memset(mybuf, '*', 63); mybuf[63] = '\0'; 124 ret = strerror_r(1, mybuf, 10); 125 printf("strerror_r on short buffer returns %d (%s)\n", ret, mybuf); 126 } 127 #endif 128