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Annotated edit history of shred(1) version 1, including all changes. View license author blame.
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1 perry 1 SHRED
2 !!!SHRED
3 NAME
4 SYNOPSIS
5 DESCRIPTION
6 AUTHOR
7 REPORTING BUGS
8 COPYRIGHT
9 SEE ALSO
10 ----
11 !!NAME
12
13
14 shred - delete a file securely, first overwriting it to hide its contents
15 !!SYNOPSIS
16
17
18 __shred__ [[''OPTIONS''] ''FILE'' [[...]
19 !!DESCRIPTION
20
21
22 Overwrite the specified FILE(s) repeatedly, in order to make
23 it harder for even very expensive hardware probing to
24 recover the data.
25
26
27 __-f__, __--force__
28
29
30 change permissions to allow writing if
31 necessary
32
33
34 __-n__, __--iterations__=''N''
35
36
37 Overwrite N times instead of the default (25)
38
39
40 __-s__, __--size__=''N''
41
42
43 shred this many bytes (suffixes like k, M, G
44 accepted)
45
46
47 __-u__, __--remove__
48
49
50 truncate and remove file after overwriting
51
52
53 __-v__, __--verbose__
54
55
56 show progress
57
58
59 __-x__, __--exact__
60
61
62 do not round file sizes up to the next full
63 block
64
65
66 __-z__, __--zero__
67
68
69 add a final overwrite with zeros to hide
70 shredding
71
72
73 -
74
75
76 shred standard output
77
78
79 __--help__
80
81
82 display this help and exit
83
84
85 __--version__
86
87
88 print version information and exit
89
90
91 Delete FILE(s) if __--remove__ (-u) is specified. The
92 default is not to remove the files because it is common to
93 operate on device files like /dev/hda, and those files
94 usually should not be removed. When operating on regular
95 files, most people use the __--remove__
96 option.
97
98
99 CAUTION: Note that shred relies on a very important
100 assumption: that the filesystem overwrites data in place.
101 This is the traditional way to do things, but many modern
102 filesystem designs do not satisfy this assumption. The
103 following are examples of filesystems on which shred is not
104 effective:
105
106
107 * log-structured or journaled filesystems, such as those
108 supplied with
109
110
111 AIX and Solaris (and JFS, ReiserFS, XFS, etc.)
112
113
114 * filesystems that write redundant data and carry on even if
115 some writes
116
117
118 fail, such as RAID-based filesystems
119
120
121 * filesystems that make snapshots, such as Network
122 Appliance's NFS server
123
124
125 * filesystems that cache in temporary locations, such as
126 NFS
127
128
129 version 3 clients
130
131
132 * compressed filesystems
133 !!AUTHOR
134
135
136 Written by Colin Plumb.
137 !!REPORTING BUGS
138
139
140 Report bugs to
141 !!COPYRIGHT
142
143
144 Copyright 2001 Free Software Foundation, Inc.
145 This is free software; see the source for copying
146 conditions. There is NO warranty; not even for
147 MERCHANTABILITY or FITNESS FOR A PARTICULAR
148 PURPOSE.
149 !!SEE ALSO
150
151
152 The full documentation for __shred__ is maintained as a
153 Texinfo manual. If the __info__ and __shred__ programs
154 are properly installed at your site, the
155 command
156
157
158 __info shred__
159
160
161 should give you access to the complete manual.
162 ----
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