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 45 int 46 strerror_r(int errnum, char *strerrbuf, size_t buflen) 47 { 48 #define UPREFIX "Unknown error: " 49 unsigned int uerr; 50 char *p, *t; 51 char tmp[40]; /* 64-bit number + slop */ 52 int len; 53 54 uerr = errnum; /* convert to unsigned */ 55 if (uerr < sys_nerr) { 56 len = strlcpy(strerrbuf, (char *)sys_errlist[uerr], buflen); 57 return (len <= buflen) ? 0 : ERANGE; 58 } 59 60 /* Print unknown errno by hand so we don't link to stdio(3). */ 61 t = tmp; 62 if (errnum < 0) 63 uerr = -uerr; 64 do { 65 *t++ = "0123456789"[uerr % 10]; 66 } while (uerr /= 10); 67 68 if (errnum < 0) 69 *t++ = '-'; 70 71 strlcpy(strerrbuf, UPREFIX, buflen); 72 for (p = strerrbuf + sizeof(UPREFIX) - 1; p < strerrbuf + buflen; ) { 73 *p++ = *--t; 74 if (t <= tmp) 75 break; 76 } 77 78 if (p < strerrbuf + buflen) { 79 *p = '\0'; 80 return 0; 81 } 82 83 return ERANGE; 84 } 85 86 87 /* 88 * NOTE: the following length should be enough to hold the longest defined 89 * error message in sys_errlist, defined in ../gen/errlst.c. This is a WAG 90 * that is better than the previous value. 91 */ 92 #define ERR_LEN 64 93 94 char * 95 strerror(num) 96 int num; 97 { 98 unsigned int uerr; 99 static char ebuf[ERR_LEN]; 100 101 uerr = num; /* convert to unsigned */ 102 if (uerr < sys_nerr) 103 return (char *)sys_errlist[uerr]; 104 105 /* strerror can't fail so handle truncation semi-elegantly */ 106 if (strerror_r(num, ebuf, (size_t) ERR_LEN) != 0) 107 ebuf[ERR_LEN - 1] = '\0'; 108 109 return ebuf; 110 } 111 112 113 #ifdef STANDALONE_TEST 114 main() 115 { 116 char mybuf[64]; 117 int ret; 118 119 printf("strerror(47) yeilds: %s\n", strerror(47)); 120 strerror_r(11, mybuf, 64); 121 printf("strerror_r(11) yeilds: %s\n", mybuf); 122 strerror_r(1234, mybuf, 64); 123 printf("strerror_r(1234) yeilds: %s\n", mybuf); 124 memset(mybuf, '*', 63); 125 ret = strerror_r(4321, mybuf, 16); 126 printf("strerror_r on short buffer returns %d (%s)\n", ret, mybuf); 127 } 128 #endif 129