1 /* addext.c -- add an extension to a file name 2 Copyright (C) 1990, 1997-1999, 2001-2003, 2005-2006 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 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ 18 19 /* Written by David MacKenzie <djm@gnu.ai.mit.edu> and Paul Eggert */ 20 21 #include <config.h> 22 23 #ifndef HAVE_DOS_FILE_NAMES 24 # define HAVE_DOS_FILE_NAMES 0 25 #endif 26 #ifndef HAVE_LONG_FILE_NAMES 27 # define HAVE_LONG_FILE_NAMES 0 28 #endif 29 30 #include "backupfile.h" 31 32 #include <limits.h> 33 #ifndef _POSIX_NAME_MAX 34 # define _POSIX_NAME_MAX 14 35 #endif 36 37 #include <sys/types.h> 38 #if HAVE_STRING_H 39 # include <string.h> 40 #else 41 # include <strings.h> 42 #endif 43 44 #include <unistd.h> 45 46 #include "basename.h" 47 48 /* Append to FILENAME the extension EXT, unless the result would be too long, 49 in which case just append the character E. */ 50 51 void 52 addext (char *filename, char const *ext, char e) 53 { 54 char *s = basename (filename); 55 size_t slen = strlen (s), extlen = strlen (ext); 56 long slen_max = -1; 57 58 #if HAVE_PATHCONF && defined _PC_NAME_MAX 59 if (slen + extlen <= _POSIX_NAME_MAX && ! HAVE_DOS_FILE_NAMES) 60 /* The file name is so short there's no need to call pathconf. */ 61 slen_max = _POSIX_NAME_MAX; 62 else if (s == filename) 63 slen_max = pathconf (".", _PC_NAME_MAX); 64 else 65 { 66 char c = *s; 67 *s = 0; 68 slen_max = pathconf (filename, _PC_NAME_MAX); 69 *s = c; 70 } 71 #endif 72 if (slen_max < 0) 73 slen_max = HAVE_LONG_FILE_NAMES ? 255 : 14; 74 75 if (HAVE_DOS_FILE_NAMES && slen_max <= 12) 76 { 77 /* Live within DOS's 8.3 limit. */ 78 char *dot = strchr (s, '.'); 79 if (dot) 80 { 81 slen -= dot + 1 - s; 82 s = dot + 1; 83 slen_max = 3; 84 } 85 else 86 slen_max = 8; 87 extlen = 9; /* Don't use EXT. */ 88 } 89 90 if (slen + extlen <= slen_max) 91 strcpy (s + slen, ext); 92 else 93 { 94 if (slen_max <= slen) 95 slen = slen_max - 1; 96 s[slen] = e; 97 s[slen + 1] = 0; 98 } 99 } 100