1/* addext.c -- add an extension to a file name 2 Copyright (C) 1990, 1997, 1998, 1999 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 52char *base_name PARAMS ((char const *)); 53 54/* Append to FILENAME the extension EXT, unless the result would be too long, 55 in which case just append the character E. */ 56 57void 58addext (char *filename, char const *ext, int e) 59{ 60 char *s = base_name (filename); 61 size_t slen = strlen (s), extlen = strlen (ext); 62 long slen_max = -1; 63 64#if HAVE_PATHCONF && defined _PC_NAME_MAX 65 if (slen + extlen <= _POSIX_NAME_MAX && ! HAVE_DOS_FILE_NAMES) 66 /* The file name is so short there's no need to call pathconf. */ 67 slen_max = _POSIX_NAME_MAX; 68 else if (s == filename) 69 slen_max = pathconf (".", _PC_NAME_MAX); 70 else 71 { 72 char c = *s; 73 *s = 0; 74 slen_max = pathconf (filename, _PC_NAME_MAX); 75 *s = c; 76 } 77#endif 78 if (slen_max < 0) 79 slen_max = HAVE_LONG_FILE_NAMES ? 255 : 14; 80 81 if (HAVE_DOS_FILE_NAMES && slen_max <= 12) 82 { 83 /* Live within DOS's 8.3 limit. */ 84 char *dot = strchr (s, '.'); 85 if (dot) 86 { 87 slen -= dot + 1 - s; 88 s = dot + 1; 89 slen_max = 3; 90 } 91 else 92 slen_max = 8; 93 extlen = 9; /* Don't use EXT. */ 94 } 95 96 if (slen + extlen <= slen_max) 97 strcpy (s + slen, ext); 98 else 99 { 100 if (slen_max <= slen) 101 slen = slen_max - 1; 102 s[slen] = e; 103 s[slen + 1] = 0; 104 } 105} 106