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Diffstat (limited to 'lib/dirname-lgpl.c')
-rw-r--r-- | lib/dirname-lgpl.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/lib/dirname-lgpl.c b/lib/dirname-lgpl.c new file mode 100644 index 0000000..a40f6a9 --- /dev/null +++ b/lib/dirname-lgpl.c @@ -0,0 +1,86 @@ +/* dirname.c -- return all but the last element in a file name + + Copyright (C) 1990, 1998, 2000-2001, 2003-2006, 2009-2018 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; +} |