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SHRED(1)			      FSF			      SHRED(1)

NAME
       shred  -	 delete	a file securely, first overwriting it to hide its con-
       tents

SYNOPSIS
       shred [OPTIONS] FILE [...]

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

       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 (25)

       -s, --size=N
	      shred this many bytes (suffixes like K, M, G accepted)

       -u, --remove
	      truncate and remove file after overwriting

       -v, --verbose
	      show progress

       -x, --exact
	      do not round file	sizes up to the	next full block

       -z, --zero
	      add a final overwrite with zeros to hide shredding

       -      shred standard output

       --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.	 When  operat-
       ing on regular files, most people use the --remove option.

       CAUTION:	 Note  that  shred relies on a very important assumption: that
       the filesystem overwrites data in place.	 This is the  traditional  way
       to  do  things,	but many modern	filesystem designs do not satisfy this
       assumption.  The	following are examples of filesystems on  which	 shred
       is not effective:

       * log-structured	or journaled filesystems, such as those	supplied with

	      AIX and Solaris (and JFS,	ReiserFS, XFS, Ext3, etc.)

       *  filesystems  that  write  redundant  data  and carry on even if some
       writes

	      fail, such as RAID-based filesystems

       * filesystems that make snapshots,  such	 as  Network  Appliance's  NFS
       server

       * filesystems that cache	in temporary locations,	such as	NFS

	      version 3	clients

       * compressed filesystems

       In  addition, file system backups and remote mirrors may	contain	copies
       of the file that	cannot be removed, and that will allow a shredded file
       to be recovered later.

AUTHOR
       Written by Colin	Plumb.

REPORTING BUGS
       Report bugs to <bug-coreutils@gnu.org>.

COPYRIGHT
       Copyright (C) 2002 Free Software	Foundation, Inc.
       This is free software; see the source for copying conditions.  There is
       NO warranty; not	even for MERCHANTABILITY or FITNESS FOR	 A  PARTICULAR
       PURPOSE.

SEE ALSO
       The full	documentation for shred	is maintained as a Texinfo manual.  If
       the info	and shred programs are properly	installed at  your  site,  the
       command

	      info shred

       should give you access to the complete manual.

shred (coreutils) 4.5.3		 February 2003			      SHRED(1)

NAME | SYNOPSIS | DESCRIPTION | AUTHOR | REPORTING BUGS | COPYRIGHT | SEE ALSO

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