lib/libc/string/strerror.c

   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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)strerror.c       8.1 (Berkeley) 6/4/93
  30  * $FreeBSD: src/lib/libc/string/strerror.c,v 1.16 2007/01/09 00:28:12 imp Exp $
  31  * $DragonFly: src/lib/libc/string/strerror.c,v 1.2 2003/06/17 04:26:46 dillon Exp $
  32  */
  33
  34 #if defined(NLS)
  35 #include <nl_types.h>
  36 #endif
  37
  38 #include <limits.h>
  39 #include <errno.h>
  40 #include <string.h>
  41 #include <stdio.h>
  42
  43 #define UPREFIX         "Unknown error"
  44
  45 /*
  46  * Define a buffer size big enough to describe a 64-bit signed integer
  47  * converted to ASCII decimal (19 bytes), with an optional leading sign
  48  * (1 byte); finally, we get the prefix, delimiter (": ") and a trailing
  49  * NUL from UPREFIX.
  50  */
  51 #define EBUFSIZE        (20 + 2 + sizeof(UPREFIX))
  52
  53 /*
  54  * Doing this by hand instead of linking with stdio(3) avoids bloat for
  55  * statically linked binaries.
  56  */
  57 static void
  58 errstr(int num, char *uprefix, char *buf, size_t len)
  59 {
  60         char *t;
  61         unsigned int uerr;
  62         char tmp[EBUFSIZE];
  63
  64         t = tmp + sizeof(tmp);
  65         *--t = '\0';
  66         uerr = (num >= 0) ? num : -num;
  67         do {
  68                 *--t = "0123456789"[uerr % 10];
  69         } while (uerr /= 10);
  70         if (num < 0)
  71                 *--t = '-';
  72         *--t = ' ';
  73         *--t = ':';
  74         strlcpy(buf, uprefix, len);
  75         strlcat(buf, t, len);
  76 }
  77
  78 int
  79 strerror_r(int errnum, char *strerrbuf, size_t buflen)
  80 {
  81         int retval = 0;
  82 #if defined(NLS)
  83         int saved_errno = errno;
  84         nl_catd catd;
  85         catd = catopen("libc", NL_CAT_LOCALE);
  86 #endif
  87
  88         if (errnum < 1 || errnum >= sys_nerr) {
  89                 errstr(errnum,
  90 #if defined(NLS)
  91                         catgets(catd, 1, 0xffff, UPREFIX),
  92 #else
  93                         UPREFIX,
  94 #endif
  95                         strerrbuf, buflen);
  96                 retval = EINVAL;
  97         } else {
  98                 if (strlcpy(strerrbuf,
  99 #if defined(NLS)
 100                         catgets(catd, 1, errnum, sys_errlist[errnum]),
 101 #else
 102                         sys_errlist[errnum],
 103 #endif
 104                         buflen) >= buflen)
 105                 retval = ERANGE;
 106         }
 107
 108 #if defined(NLS)
 109         catclose(catd);
 110         errno = saved_errno;
 111 #endif
 112
 113         return (retval);
 114 }
 115
 116 char *
 117 strerror(int num)
 118 {
 119         static char ebuf[NL_TEXTMAX];
 120
 121         if (strerror_r(num, ebuf, sizeof(ebuf)) != 0)
 122         errno = EINVAL;
 123         return (ebuf);
 124 }