Typo fixes to man page.

[vbig.git] / vbig.1

diff --git a/vbig.1 b/vbig.1
index be514251908488409289c2f831330e7b6ff516b8..134caae80b0f4d3831667bb398b56f1f9b715b7d 100644 (file)
--- a/vbig.1
+++ b/vbig.1
@@ -1,6 +1,7 @@
 \"
 \" This file is part of vbig.
 \" Copyright (C) 2011 Richard Kettlewell
 \"
 \" This file is part of vbig.
 \" Copyright (C) 2011 Richard Kettlewell

+\" Copyright (C) 2013 Ian Jackson

 \"
 \" This program is free software: you can redistribute it and/or modify
 \" it under the terms of the GNU General Public License as published by
 \"
 \" This program is free software: you can redistribute it and/or modify
 \" it under the terms of the GNU General Public License as published by


@@ -21,26 +22,53 @@ vbig \- create or verify a large but pseudo-random file
 .SH SYNOPSIS
 \fBvbig \fR[\fB--seed \fRSEED\fR] [\fB--both\fR|\fB--create\fR|\fB--verify\fR] \fIPATH \fR[\fISIZE\fR]
 .br
 .SH SYNOPSIS
 \fBvbig \fR[\fB--seed \fRSEED\fR] [\fB--both\fR|\fB--create\fR|\fB--verify\fR] \fIPATH \fR[\fISIZE\fR]
 .br

-\fBvbig --help
+\fBvbig \-\-help

 .br
 .br

-\fBvbig --version
+\fBvbig \-\-version

 .SH DESCRIPTION
 \fBvbig\fR creates a file of specified size full of predictable
 psuedo-random data, and/or verifies that it has the expected contents.
 The intended use is to test whether storage media really do what they
 say on the tin.
 .PP
 .SH DESCRIPTION
 \fBvbig\fR creates a file of specified size full of predictable
 psuedo-random data, and/or verifies that it has the expected contents.
 The intended use is to test whether storage media really do what they
 say on the tin.
 .PP

+By default vbig will generate a new random seed, write data to the
+specified file or device until the device is full, read the data back
+to check that everything written was properly stored, and report
+the device's size.  Ideally, if you have privilege to do so, you
+would also specify \fB-f\fR (to flush the operating system disk
+cache between the write and read).  Also you probably want \fB-p\fR.
+.PP
+\fIPATH\fR can refer to an ordinary file on a mounted file system,
+which vbig will create or truncate as necessary, or a block device.
+Note that if it's a file, vbig won't delete it after it's done.  Also,
+be careful when specifying a block device - don't accidentally
+overwrite a filesystem you care about!  vbig doesn't do sanity checks
+and is as dangerous as \fBdd\fR.
+.PP

 \fISIZE\fR may end with \fBK\fR, \fBM\fR or \fBG\fR to select (binary)
 kilobytes, megabytes or gigabytes.
 The size is mandatory when creating a file but optional when verifying
 \fISIZE\fR may end with \fBK\fR, \fBM\fR or \fBG\fR to select (binary)
 kilobytes, megabytes or gigabytes.
 The size is mandatory when creating a file but optional when verifying

-it, unless \-\-entire is specified.  If \fBSIZE\fR not specified when
+it, unless \-\-entire is specified.  If \fISIZE\fR not specified when

 writing-then-verifying, it is as if \fB\-\-entire\fR was specified.
 writing-then-verifying, it is as if \fB\-\-entire\fR was specified.

+.PP
+If no seed or seed file is specified:
+in \fB--both\fR mode a fresh random seed is read from the system's
+random number generator; in other modes a fixed default seed is used.

 .SH OPTIONS
 .TP
 .B --seed\fR, \fB-s \fISEED
 Specifies the random seed to use.
 Optional.
 .TP
 .SH OPTIONS
 .TP
 .B --seed\fR, \fB-s \fISEED
 Specifies the random seed to use.
 Optional.
 .TP

+.B --seed-file\fR, \fB-S \fISEED-FILE
+Specifies wehre the random seed should be read from.  The
+first \fISEED-LENGTH\fR bytes will be used, or the whole file
+if it is shorter.
+.TP
+.B --seed-length\fR, \fB-L \fISEED-LENGTH
+Specifies the (maximum) seed length in bytes.
+Optional; default is 2048.
+.TP

 .B --both\fR, \fB-b
 Selects both mode.
 \fIPATH\fR will be filled with \fISIZE\fR psuedo-random bytes and
 .B --both\fR, \fB-b
 Selects both mode.
 \fIPATH\fR will be filled with \fISIZE\fR psuedo-random bytes and


@@ -60,6 +88,9 @@ by the equivalent \fB--create\fR call.
 Flush cached data after creating the file or before verifying it.
 On some platforms, only root can use this option.
 .TP
 Flush cached data after creating the file or before verifying it.
 On some platforms, only root can use this option.
 .TP

+.B --progress\fR, \fB-p
+Show the progress (in bytes) on stdout.
+.TP

 .B --entire\fR, \fB-e
 When writing, keep going until the device is full (No space left
 on device).  When reading, keep going until the end of the file
 .B --entire\fR, \fB-e
 When writing, keep going until the device is full (No space left
 on device).  When reading, keep going until the end of the file


@@ -69,7 +100,7 @@ written or verified will be printed to stdout.
 .B --help\fR, \fB-h
 Displays a usage message.
 .TP
 .B --help\fR, \fB-h
 Displays a usage message.
 .TP

-.B --version\fR, \fB-h
+.B --version\fR, \fB-V

 Displays the version strings.
 .SH AUTHOR
 Richard Kettlewell <rjk@greenend.org.uk>
 Displays the version strings.
 .SH AUTHOR
 Richard Kettlewell <rjk@greenend.org.uk>