| /* dirname.c -- return all but the last element in a file name | |
| Copyright (C) 1990, 1998, 2000-2001, 2003-2006, 2009-2023 Free Software | |
| Foundation, Inc. | |
| This file is free software: you can redistribute it and/or modify | |
| it under the terms of the GNU Lesser General Public License as | |
| published by the Free Software Foundation; either version 2.1 of the | |
| License, or (at your option) any later version. | |
| This file 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 Lesser General Public License for more details. | |
| You should have received a copy of the GNU Lesser General Public License | |
| along with this program. If not, see <https://www.gnu.org/licenses/>. */ | |
| /* 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; | |
| } | |