/* 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 ( -DCHECK_BUF ) to allow a quick check * on the buffer length when the sys_errorlist is modified. * * Added the option WANT_ERRORLIST for low-memory applications to omit the * error message strings and only output the error number. */ #define WANT_ERRORLIST 1 #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); #if WANT_ERRORLIST static char retbuf[48]; #else static char retbuf[33]; /* 33 is sufficient for 32 bit ints */ #endif 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 WANT_ERRORLIST if ((err >= 0) && (err < sys_nerr)) { strcpy(retbuf, sys_errlist[err]); return retbuf; } #endif /* 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; } #ifdef CHECK_BUF /* quick way to check buffer length */ #include <stdio.h> #include <stdlib.h> int main(void) { int max = 0; int j, retcode; char *p; #if WANT_ERRORLIST int i; #endif retcode = EXIT_SUCCESS; #if WANT_ERRORLIST for ( i=0 ; i < sys_nerr ; i++ ) { j = strlen(sys_errlist[i])+1; if (j > max) max = j; } #endif p = strerror(INT_MIN); j = strlen(p)+1; if (j > max) { max = j; printf("strerror.c - Test of INT_MIN: <%s> %d\n", p, j); } if (sizeof(retbuf) != max) { printf("Error: strerror.c - dimension of retbuf should be = %d\n", max); retcode = EXIT_FAILURE; } printf("Passed.\n"); return retcode; } #endif