1/* addext.c -- add an extension to a file name 2 Copyright (C) 1990, 1997-1999, 2001-2003 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#include "backupfile.h" 33 34#include <limits.h> 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 "basename.h" 51 52/* Append to FILENAME the extension EXT, unless the result would be too long, 53 in which case just append the character E. */ 54 55void 56addext (char *filename, char const *ext, char e) 57{ 58 char *s = basename (filename); 59 size_t slen = strlen (s), extlen = strlen (ext); 60 long slen_max = -1; 61 62#if HAVE_PATHCONF && defined _PC_NAME_MAX 63 if (slen + extlen <= _POSIX_NAME_MAX && ! HAVE_DOS_FILE_NAMES) 64 /* The file name is so short there's no need to call pathconf. */ 65 slen_max = _POSIX_NAME_MAX; 66 else if (s == filename) 67 slen_max = pathconf (".", _PC_NAME_MAX); 68 else 69 { 70 char c = *s; 71 *s = 0; 72 slen_max = pathconf (filename, _PC_NAME_MAX); 73 *s = c; 74 } 75#endif 76 if (slen_max < 0) 77 slen_max = HAVE_LONG_FILE_NAMES ? 255 : 14; 78 79 if (HAVE_DOS_FILE_NAMES && slen_max <= 12) 80 { 81 /* Live within DOS's 8.3 limit. */ 82 char *dot = strchr (s, '.'); 83 if (dot) 84 { 85 slen -= dot + 1 - s; 86 s = dot + 1; 87 slen_max = 3; 88 } 89 else 90 slen_max = 8; 91 extlen = 9; /* Don't use EXT. */ 92 } 93 94 if (slen + extlen <= slen_max) 95 strcpy (s + slen, ext); 96 else 97 { 98 if (slen_max <= slen) 99 slen = slen_max - 1; 100 s[slen] = e; 101 s[slen + 1] = 0; 102 } 103} 104