1/* addext.c -- add an extension to a file name 2 Copyright 1990, 1997, 1998, 1999, 2001 Free Software Foundation, Inc. 3 4 This program is free software; you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; either version 2, or (at your option) 7 any later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program; see the file COPYING. 16 If not, write to the Free Software Foundation, 17 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ 18 19/* Written by David MacKenzie <djm@gnu.ai.mit.edu> and Paul Eggert */ 20 21#if HAVE_CONFIG_H 22# include <config.h> 23#endif 24 25#ifndef HAVE_DOS_FILE_NAMES 26# define HAVE_DOS_FILE_NAMES 0 27#endif 28#ifndef HAVE_LONG_FILE_NAMES 29# define HAVE_LONG_FILE_NAMES 0 30#endif 31 32#if HAVE_LIMITS_H 33# include <limits.h> 34#endif 35#ifndef _POSIX_NAME_MAX 36# define _POSIX_NAME_MAX 14 37#endif 38 39#include <sys/types.h> 40#if HAVE_STRING_H 41# include <string.h> 42#else 43# include <strings.h> 44#endif 45 46#if HAVE_UNISTD_H 47# include <unistd.h> 48#endif 49 50#include <errno.h> 51#ifndef errno 52extern int errno; 53#endif 54 55#include "backupfile.h" 56#include "dirname.h" 57 58/* Append to FILENAME the extension EXT, unless the result would be too long, 59 in which case just append the character E. */ 60 61void 62addext (char *filename, char const *ext, int e) 63{ 64 char *s = base_name (filename); 65 size_t slen = base_len (s); 66 size_t extlen = strlen (ext); 67 size_t slen_max = HAVE_LONG_FILE_NAMES ? 255 : _POSIX_NAME_MAX; 68 69#if HAVE_PATHCONF && defined _PC_NAME_MAX 70 if (_POSIX_NAME_MAX < slen + extlen || HAVE_DOS_FILE_NAMES) 71 { 72 /* The new base name is long enough to require a pathconf check. */ 73 long name_max; 74 errno = 0; 75 if (s == filename) 76 name_max = pathconf (".", _PC_NAME_MAX); 77 else 78 { 79 char c = *s; 80 if (! ISSLASH (c)) 81 *s = 0; 82 name_max = pathconf (filename, _PC_NAME_MAX); 83 *s = c; 84 } 85 if (0 <= name_max || errno == 0) 86 slen_max = name_max == (size_t) name_max ? name_max : -1; 87 } 88#endif 89 90 if (HAVE_DOS_FILE_NAMES && slen_max <= 12) 91 { 92 /* Live within DOS's 8.3 limit. */ 93 char *dot = strchr (s, '.'); 94 if (dot) 95 { 96 slen -= dot + 1 - s; 97 s = dot + 1; 98 slen_max = 3; 99 } 100 else 101 slen_max = 8; 102 extlen = 9; /* Don't use EXT. */ 103 } 104 105 if (slen + extlen <= slen_max) 106 strcpy (s + slen, ext); 107 else 108 { 109 if (slen_max <= slen) 110 slen = slen_max - 1; 111 s[slen] = e; 112 s[slen + 1] = 0; 113 } 114} 115