DragonFly On-Line Manual Pages
UNDELETE(2) DragonFly System Calls Manual UNDELETE(2)
undelete -- attempt to recover a deleted file
Standard C Library (libc, -lc)
undelete(const char *path);
The undelete() function attempts to recover the deleted file named by
path. Currently, this works only when the named object is a whiteout in
a union filesystem. The system call removes the whiteout causing any
objects in a lower layer of the union stack to become visible once more.
Eventually, the undelete() functionality may be expanded to other
filesystems able to recover deleted files such as the log-structured
The undelete() function returns the value 0 if successful; otherwise the
value -1 is returned and the global variable errno is set to indicate the
The undelete() succeeds unless:
[ENOTDIR] A component of the path prefix is not a directory.
[ENAMETOOLONG] A component of a pathname exceeded 255 characters, or
an entire path name exceeded 1023 characters.
[EEXIST] The path does not reference a whiteout.
[ENOENT] The named whiteout does not exist.
[EACCES] Search permission is denied for a component of the
[EACCES] Write permission is denied on the directory containing
the name to be undeleted.
[ELOOP] Too many symbolic links were encountered in translat-
ing the pathname.
[EPERM] The directory containing the name is marked sticky,
and the containing directory is not owned by the
effective user ID.
[EIO] An I/O error occurred while updating the directory
[EROFS] The name resides on a read-only file system.
[EFAULT] Path points outside the process's allocated address
An undelete() function call first appeared in 4.4BSD-Lite.
DragonFly 4.3 October 18, 1994 DragonFly 4.3