srm(1) - f31

1srm(1)                                                                  srm(1)
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NAME

6       srm - securely remove files or directories
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SYNOPSIS

9       srm [OPTION]... FILE...
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DESCRIPTION

12       srm  removes each specified file by overwriting, renaming, and truncat‐
13       ing it before unlinking.  This prevents other people from undeleting or
14       recovering  any  information  about the file from the command line.  By
15       default srm uses the simple mode to overwrite the file's contents.  You
16       can  choose  a  different  overwrite mode with --dod, --doe, --openbsd,
17       --rcmp, --gutmann.  If you specify more than one mode option, the  last
18       option is used.
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20       You  can  use  srm  to overwrite block devices.  The device node is not
21       removed after overwriting.  This feature is available on Linux.   Files
22       with multiple hard links will be unlinked but not overwritten.
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24       srm,  like  every  program  that  uses the getopt function to parse its
25       arguments, lets you use the -- option to indicate  that  all  following
26       arguments are non-options.  To remove a file called `-f' in the current
27       directory, you could type either
28              rm -- -f
29       or
30              rm ./-f
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OPTIONS

33       -d, --directory
34              ignored (for compatibility with rm(1))
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36       -f, --force
37              ignore nonexistent files, never prompt
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39       -i, --interactive
40              prompt before any removal
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42       -r, -R, --recursive
43              remove the contents of directories recursively
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45       -x, --one-file-system
46              when removing a hierarchy recursively, skip any  directory  that
47              is  on  a  file  system different from that of the corresponding
48              command line argument.  (Not supported on Windows)
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50       -s, --simple
51              Overwrite the file with a single pass of 0x00  bytes.   This  is
52              the default mode.
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54       -P, --openbsd
55              OpenBSD compatible rm.  Files are overwritten three times, first
56              with the byte 0xFF, then 0x00, and then 0xFF again, before  they
57              are deleted.
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59       -D, --dod
60              US Dod compliant 7-pass overwrite.
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62       -E, --doe
63              US DoE compliant 3-pass overwrite.  Twice with a random pattern,
64              finally       with       the       bytes       "DoE".        See
65              http://cio.energy.gov/CS-11_Clearing_and_Media_Sanitiza‐
66              tion_Guidance.pdf for details.
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68       -G, --gutmann
69              Use      the      35-pass       Gutmann       method.        See
70              http://en.wikipedia.org/wiki/Gutmann_method for details.
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72       -C, --rcmp
73              Royal Canadian Mounted Police compliant 3-pass overwrite.  First
74              pass writes 0x00 bytes.  Second pass writes 0xFF  bytes.   Third
75              pass       writes       "RCMP".        See      https://www.cse-
76              cst.gc.ca/en/node/270/html/10572 for details.
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78       -v, --verbose
79              explain what is being done.  Specify this option multiple  times
80              to increase verbosity.
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82       -h, --help
83              display this help and exit.
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85       -V, --version
86              output version information and exit.
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SIGNALS

89       SIGINFO, SIGUSR2
90              show current write position and filename handled.
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ENTIRE HARD DISKS

93       srm  can  write to block devices on Linux.  You can use srm to securely
94       delete an entire hard disk, however you should only do this for classic
95       magnetic  drives.  The modern solid state disks (SSD) have a faster and
96       better way to erase all contents, Secure Erase.  For a Linux  operating
97       system see https://ata.wiki.kernel.org/index.php/ATA_Secure_Erase
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NOTES

100       srm can not remove write protected files owned by another user, regard‐
101       less of the permissions on the directory containing the file.
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103       Development and discussion of srm is  carried  out  at  https://source‐
104       forge.net/projects/srm/ which is also accessible via http://srm.source‐
105       forge.net/.  See http://en.wikipedia.org/wiki/Data_remanence for a gen‐
106       eral discussion about overwriting data.
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