coreutils (9.4)
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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 op‐
erate 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 obfus‐
cate 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 plat‐
forms 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/>
COPYRIGHT
Copyright © 2023 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/li‐
censes/gpl.html>.
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 <https://www.gnu.org/software/coreutils/shred>
or available locally via: info '(coreutils) shred invocation'
GNU coreutils 9.4 August 2023 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 op‐
erate 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 obfus‐
cate 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 plat‐
forms 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/>
COPYRIGHT
Copyright © 2023 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/li‐
censes/gpl.html>.
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 <https://www.gnu.org/software/coreutils/shred>
or available locally via: info '(coreutils) shred invocation'
GNU coreutils 9.4 August 2023 SHRED(1)