Unix/Linux Go Back    

RedHat 9 (Linux i386) - man page for shred (redhat section 1)

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)

SHRED(1)				       FSF					 SHRED(1)

       shred - delete a file securely, first overwriting it to hide its contents

       shred [OPTIONS] FILE [...]

       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

	      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 operating on regular files,  most  people  use  the  --remove

       CAUTION:  Note that shred relies on a very important assumption: that the filesystem over-
       writes data in place.  This is the traditional way to do things, but many modern  filesys-
       tem  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.

       Written by Colin Plumb.

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

       Copyright (C) 2002 Free Software Foundation, Inc.
       This  is  free software; see the source for copying conditions.	There is NO warranty; not

       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)
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums

All times are GMT -4. The time now is 05:36 AM.