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 visible once more.
Eventually, the
undelete
() functionality may
be expanded to other file systems able to recover deleted files such as the
log-structured 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 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 path prefix.
- [
EACCES
]
- Write permission is denied on the directory containing the name to be
undeleted.
- [
ELOOP
]
- Too many symbolic links were encountered in translating 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 system.
- [
EFAULT
]
- The path argument points outside the
process's allocated address space.
SEE ALSO¶
unlink(2),
mount_unionfs(8)
HISTORY¶
The
undelete
() system call first appeared in
4.4BSD-Lite.