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-rw-r--r--lib/dirname-lgpl.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/lib/dirname-lgpl.c b/lib/dirname-lgpl.c
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+/* dirname.c -- return all but the last element in a file name
+
+ Copyright (C) 1990, 1998, 2000-2001, 2003-2006, 2009-2022 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/>. */
+
+#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;
+}