SHRED(1) User Commands 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:
Report any translation bugs to
COPYRIGHT
Copyright © 2022 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later .
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
Full documentation
or available locally via: info '(coreutils) shred invocation'
GNU coreutils 9.1 September 2022 SHRED(1)