/* Work around unlink bugs.
- Copyright (C) 2009 Free Software Foundation, Inc.
+ Copyright (C) 2009, 2010 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
if (len && ISSLASH (name[len - 1]))
{
/* We can't unlink(2) something if it doesn't exist. If it does
- exist, then it resolved to a directory, due to the trailing
- slash, and POSIX requires that the unlink attempt to remove
- that directory (which would leave the symlink dangling).
- Unfortunately, Solaris 9 is one of the platforms where the
- root user can unlink directories, and we don't want to
- cripple this behavior on real directories, even if it is
- seldom needed (at any rate, it's nicer to let coreutils'
- unlink(1) give the correct errno for non-root users). But we
- don't know whether name was an actual directory, or a symlink
- to a directory; and due to the bug of ignoring trailing
- slash, Solaris 9 would end up successfully unlinking the
- symlink instead of the directory. Technically, we could use
- realpath to find the canonical directory name to attempt
- deletion on. But that is a lot of work for a corner case; so
- we instead just use an lstat on the shortened name, and
- reject symlinks with trailing slashes. The root user of
- unlink(1) will just have to live with the rule that they
- can't delete a directory via a symlink. */
+ exist, then it resolved to a directory, due to the trailing
+ slash, and POSIX requires that the unlink attempt to remove
+ that directory (which would leave the symlink dangling).
+ Unfortunately, Solaris 9 is one of the platforms where the
+ root user can unlink directories, and we don't want to
+ cripple this behavior on real directories, even if it is
+ seldom needed (at any rate, it's nicer to let coreutils'
+ unlink(1) give the correct errno for non-root users). But we
+ don't know whether name was an actual directory, or a symlink
+ to a directory; and due to the bug of ignoring trailing
+ slash, Solaris 9 would end up successfully unlinking the
+ symlink instead of the directory. Technically, we could use
+ realpath to find the canonical directory name to attempt
+ deletion on. But that is a lot of work for a corner case; so
+ we instead just use an lstat on the shortened name, and
+ reject symlinks with trailing slashes. The root user of
+ unlink(1) will just have to live with the rule that they
+ can't delete a directory via a symlink. */
struct stat st;
result = lstat (name, &st);
if (result == 0)
- {
- /* Trailing NUL will overwrite the trailing slash. */
- char *short_name = malloc (len);
- if (!short_name)
- {
- errno = EPERM;
- return -1;
- }
- memcpy (short_name, name, len);
- while (len && ISSLASH (short_name[len - 1]))
- short_name[--len] = '\0';
- if (len && (lstat (short_name, &st) || S_ISLNK (st.st_mode)))
- {
- free (short_name);
- errno = EPERM;
- return -1;
- }
- free (short_name);
- }
+ {
+ /* Trailing NUL will overwrite the trailing slash. */
+ char *short_name = malloc (len);
+ if (!short_name)
+ {
+ errno = EPERM;
+ return -1;
+ }
+ memcpy (short_name, name, len);
+ while (len && ISSLASH (short_name[len - 1]))
+ short_name[--len] = '\0';
+ if (len && (lstat (short_name, &st) || S_ISLNK (st.st_mode)))
+ {
+ free (short_name);
+ errno = EPERM;
+ return -1;
+ }
+ free (short_name);
+ }
}
if (!result)
result = unlink (name);