undelete(2)

NAME

undelete - attempt to recover a deleted file

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <unistd.h>
int
undelete(const char *path);

DESCRIPTION

The undelete() system call attempts to recover the deleted

file named by
path. Currently, this works only when the named object is a

whiteout in
a union file system. The system call removes the whiteout

causing any
objects in a lower layer of the union stack to become visi

ble once more.

Eventually, the undelete() functionality may be expanded to

other file
systems able to recover deleted files such as the log-struc

tured file
system.

RETURN VALUES

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
error.

ERRORS

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 charac

ters.

[EEXIST] The path does not reference a whiteout.

[ENOENT] The named whiteout does not exist.

[EACCES] Search permission is denied for a compo

nent of the

path prefix.

[EACCES] Write permission is denied on the direc

tory 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.

[EINVAL] The last component of the path is `..'.

[EIO] An I/O error occurred while updating the

directory

entry.

[EROFS] The name resides on a read-only file sys

tem.

[EFAULT] The path argument points outside the pro

cess's allo

cated address space.

SEE ALSO

unlink(2), mount_unionfs(8)

HISTORY

The undelete() system call first appeared in 4.4BSD-Lite.

BSD January 22, 2006

BSD