| /* addext.c -- add an extension to a file name |
| Copyright (C) 1990, 1997-1999, 2001-2003, 2005-2006, 2020 Free Software |
| Foundation, Inc. |
| |
| This program is free software: you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
| |
| /* Written by David MacKenzie <djm@gnu.ai.mit.edu> and Paul Eggert */ |
| |
| #include <config.h> |
| |
| #ifndef HAVE_DOS_FILE_NAMES |
| # define HAVE_DOS_FILE_NAMES 0 |
| #endif |
| #ifndef HAVE_LONG_FILE_NAMES |
| # define HAVE_LONG_FILE_NAMES 0 |
| #endif |
| |
| #include "backupfile.h" |
| |
| #include <limits.h> |
| #ifndef _POSIX_NAME_MAX |
| # define _POSIX_NAME_MAX 14 |
| #endif |
| |
| #include <sys/types.h> |
| #if HAVE_STRING_H |
| # include <string.h> |
| #else |
| # include <strings.h> |
| #endif |
| |
| #include <unistd.h> |
| |
| #include "basename-lgpl.h" |
| |
| /* Append to FILENAME the extension EXT, unless the result would be too long, |
| in which case just append the character E. */ |
| |
| void |
| addext (char *filename, char const *ext, char e) |
| { |
| char *s = last_component (filename); |
| size_t slen = strlen (s), extlen = strlen (ext); |
| long slen_max = -1; |
| |
| #if HAVE_PATHCONF && defined _PC_NAME_MAX |
| if (slen + extlen <= _POSIX_NAME_MAX && ! HAVE_DOS_FILE_NAMES) |
| /* The file name is so short there's no need to call pathconf. */ |
| slen_max = _POSIX_NAME_MAX; |
| else if (s == filename) |
| slen_max = pathconf (".", _PC_NAME_MAX); |
| else |
| { |
| char c = *s; |
| *s = 0; |
| slen_max = pathconf (filename, _PC_NAME_MAX); |
| *s = c; |
| } |
| #endif |
| if (slen_max < 0) |
| slen_max = HAVE_LONG_FILE_NAMES ? 255 : 14; |
| |
| if (HAVE_DOS_FILE_NAMES && slen_max <= 12) |
| { |
| /* Live within DOS's 8.3 limit. */ |
| char *dot = strchr (s, '.'); |
| if (dot) |
| { |
| slen -= dot + 1 - s; |
| s = dot + 1; |
| slen_max = 3; |
| } |
| else |
| slen_max = 8; |
| extlen = 9; /* Don't use EXT. */ |
| } |
| |
| if (slen + extlen <= slen_max) |
| strcpy (s + slen, ext); |
| else |
| { |
| if (slen_max <= slen) |
| slen = slen_max - 1; |
| s[slen] = e; |
| s[slen + 1] = 0; |
| } |
| } |