| /* dirname.c -- return all but the last element in a file name |
| |
| Copyright (C) 1990, 1998, 2000-2001, 2003-2006, 2009-2019 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/>. */ |
| |
| #include <config.h> |
| |
| #include "dirname.h" |
| |
| #include <stdlib.h> |
| #include <string.h> |
| |
| /* Return the length of the prefix of FILE that will be used by |
| dir_name. If FILE is in the working directory, this returns zero |
| even though 'dir_name (FILE)' will return ".". Works properly even |
| if there are trailing slashes (by effectively ignoring them). */ |
| |
| size_t |
| dir_len (char const *file) |
| { |
| size_t prefix_length = FILE_SYSTEM_PREFIX_LEN (file); |
| size_t length; |
| |
| /* Advance prefix_length beyond important leading slashes. */ |
| prefix_length += (prefix_length != 0 |
| ? (FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE |
| && ISSLASH (file[prefix_length])) |
| : (ISSLASH (file[0]) |
| ? ((DOUBLE_SLASH_IS_DISTINCT_ROOT |
| && ISSLASH (file[1]) && ! ISSLASH (file[2]) |
| ? 2 : 1)) |
| : 0)); |
| |
| /* Strip the basename and any redundant slashes before it. */ |
| for (length = last_component (file) - file; |
| prefix_length < length; length--) |
| if (! ISSLASH (file[length - 1])) |
| break; |
| return length; |
| } |
| |
| |
| /* In general, we can't use the builtin 'dirname' function if available, |
| since it has different meanings in different environments. |
| In some environments the builtin 'dirname' modifies its argument. |
| |
| Return the leading directories part of FILE, allocated with malloc. |
| Works properly even if there are trailing slashes (by effectively |
| ignoring them). Return NULL on failure. |
| |
| If lstat (FILE) would succeed, then { chdir (dir_name (FILE)); |
| lstat (base_name (FILE)); } will access the same file. Likewise, |
| if the sequence { chdir (dir_name (FILE)); |
| rename (base_name (FILE), "foo"); } succeeds, you have renamed FILE |
| to "foo" in the same directory FILE was in. */ |
| |
| char * |
| mdir_name (char const *file) |
| { |
| size_t length = dir_len (file); |
| bool append_dot = (length == 0 |
| || (FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE |
| && length == FILE_SYSTEM_PREFIX_LEN (file) |
| && file[2] != '\0' && ! ISSLASH (file[2]))); |
| char *dir = malloc (length + append_dot + 1); |
| if (!dir) |
| return NULL; |
| memcpy (dir, file, length); |
| if (append_dot) |
| dir[length++] = '.'; |
| dir[length] = '\0'; |
| return dir; |
| } |