SHRED
NAME SYNOPSIS DESCRIPTION AUTHOR REPORTING BUGS COPYRIGHT SEE ALSO
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.
-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
print 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 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:
supplied with
AIX and Solaris (and JFS, ReiserFS, XFS, etc.)
some writes
fail, such as RAID-based filesystems
Appliance's NFS server
NFS
version 3 clients
Written by Colin Plumb.
Report bugs to
Copyright 2001 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.
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.
