1.\" Copyright (c) 1994 2.\" Jan-Simon Pendry 3.\" The Regents of the University of California. All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 3. Neither the name of the University nor the names of its contributors 14.\" may be used to endorse or promote products derived from this software 15.\" without specific prior written permission. 16.\" 17.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27.\" SUCH DAMAGE. 28.\" 29.\" @(#)undelete.2 8.4 (Berkeley) 10/18/94 30.\" 31.Dd March 30, 2020 32.Dt UNDELETE 2 33.Os 34.Sh NAME 35.Nm undelete 36.Nd attempt to recover a deleted file 37.Sh LIBRARY 38.Lb libc 39.Sh SYNOPSIS 40.In unistd.h 41.Ft int 42.Fn undelete "const char *path" 43.Sh DESCRIPTION 44The 45.Fn undelete 46system call attempts to recover the deleted file named by 47.Fa path . 48Currently, this works only when the named object 49is a whiteout in a union file system. 50The system call removes the whiteout causing 51any objects in a lower layer of the 52union stack to become visible once more. 53.Pp 54Eventually, the 55.Fn undelete 56functionality may be expanded to other file systems able to recover 57deleted files such as the log-structured file system. 58.Sh RETURN VALUES 59.Rv -std undelete 60.Sh ERRORS 61The 62.Fn undelete 63succeeds unless: 64.Bl -tag -width Er 65.It Bq Er ENOTDIR 66A component of the path prefix is not a directory. 67.It Bq Er ENAMETOOLONG 68A component of a pathname exceeded 255 characters, 69or an entire path name exceeded 1023 characters. 70.It Bq Er EEXIST 71The path does not reference a whiteout. 72.It Bq Er ENOENT 73The named whiteout does not exist. 74.It Bq Er EACCES 75Search permission is denied for a component of the path prefix. 76.It Bq Er EACCES 77Write permission is denied on the directory containing the name 78to be undeleted. 79.It Bq Er ELOOP 80Too many symbolic links were encountered in translating the pathname. 81.It Bq Er EPERM 82The directory containing the name is marked sticky, 83and the containing directory is not owned by the effective user ID. 84.It Bq Er EINVAL 85The last component of the path is 86.Ql .. . 87.It Bq Er EIO 88An I/O error occurred while updating the directory entry. 89.It Bq Er EINTEGRITY 90Corrupted data was detected while reading from the file system. 91.It Bq Er EROFS 92The name resides on a read-only file system. 93.It Bq Er EFAULT 94The 95.Fa path 96argument 97points outside the process's allocated address space. 98.El 99.Sh SEE ALSO 100.Xr unlink 2 , 101.Xr mount_unionfs 8 102.Sh HISTORY 103The 104.Fn undelete 105system call first appeared in 106.Bx 4.4 Lite . 107