1 /* addext.c -- add an extension to a file name 2 Copyright (C) 1990, 1997 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 #if HAVE_LIMITS_H 35 # include <limits.h> 36 #endif 37 #ifndef _POSIX_NAME_MAX 38 #define _POSIX_NAME_MAX 14 39 #endif 40 41 #include <sys/types.h> 42 #if HAVE_STRING_H 43 # include <string.h> 44 #else 45 # include <strings.h> 46 #endif 47 48 #if HAVE_UNISTD_H 49 # include <unistd.h> 50 #endif 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 55 void 56 addext (filename, ext, e) 57 char *filename; 58 char const *ext; 59 int e; 60 { 61 char *s = base_name (filename); 62 size_t slen = strlen (s), extlen = strlen (ext); 63 long slen_max = -1; 64 65 #if HAVE_PATHCONF && defined _PC_NAME_MAX 66 if (slen + extlen <= _POSIX_NAME_MAX && ! HAVE_DOS_FILE_NAMES) 67 /* The file name is so short there's no need to call pathconf. */ 68 slen_max = _POSIX_NAME_MAX; 69 else if (s == filename) 70 slen_max = pathconf (".", _PC_NAME_MAX); 71 else 72 { 73 char c = *s; 74 *s = 0; 75 slen_max = pathconf (filename, _PC_NAME_MAX); 76 *s = c; 77 } 78 #endif 79 if (slen_max < 0) 80 slen_max = HAVE_LONG_FILE_NAMES ? 255 : 14; 81 82 if (HAVE_DOS_FILE_NAMES && slen_max <= 12) 83 { 84 /* Live within DOS's 8.3 limit. */ 85 char *dot = strchr (s, '.'); 86 if (dot) 87 { 88 slen -= dot + 1 - s; 89 s = dot + 1; 90 slen_max = 3; 91 } 92 else 93 slen_max = 8; 94 extlen = 9; /* Don't use EXT. */ 95 } 96 97 if (slen + extlen <= slen_max) 98 strcpy (s + slen, ext); 99 else 100 { 101 if (slen_max <= slen) 102 slen = slen_max - 1; 103 s[slen] = e; 104 s[slen + 1] = 0; 105 } 106 } 107