shred(1) - man - phpMan

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 expen‐
       sive 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 disk.  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  unremov‐
       able  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 © 2020 Free Software Foundation, Inc.  License GPLv3+: GNU GPL version 3  or  later
       <https://gnu.org/licenses/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 8.32                          January 2026                                    SHRED(1)