Manpages - shred.1

NAME

shred - overwrite a file to hide its contents, and optionally delete it

SYNOPSIS

shred [/OPTION/]… FILE…

DESCRIPTION

Overwrite the specified FILE(s) repeatedly, in order to make it harder for even very expensive hardware probing to recover the data.

If FILE is -, shred standard output.

Mandatory arguments to long options are mandatory for short options too.

-f, –force: change permissions to allow writing if necessary
-n, *–iterations*=/N/: overwrite N times instead of the default (3)
*–random-source*=/FILE/: get random bytes from FILE
-s, *–size*=/N/: shred this many bytes (suffixes like K, M, G accepted)
-u: deallocate and remove file after overwriting
–remove[=/HOW/]: like -u but give control on HOW to delete; See below
-v, –verbose: show progress
-x, –exact: do not round file sizes up to the next full block; this is the default for non-regular files
-z, –zero: add a final overwrite with zeros to hide shredding
–help: display this help and exit
–version: output version information and exit

Delete FILE(s) if –remove (-u) is specified. The default is not to remove the files because it is common to operate on device files like /dev/hda, and those files usually should not be removed. The optional HOW parameter indicates how to remove a directory entry: 'unlink' => use a standard unlink call. 'wipe' => also first obfuscate bytes in the name. 'wipesync' => also sync each obfuscated byte to the device. The default mode is 'wipesync', but note it can be expensive.

CAUTION: shred assumes the file system and hardware overwrite data in place. Although this is common, many platforms operate otherwise. Also, backups and mirrors may contain unremovable copies that will let a shredded file be recovered later. See the GNU coreutils manual for details.

AUTHOR

Written by Colin Plumb.

REPORTING BUGS

GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>