Merging upstream version 1.0~rc6.

Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>

7 files changed, 238 insertions, 97 deletions

diff --git a/doc/zcat.1 b/doc/zcat.1
index 0c8fc54..5e06419 100644
--- a/doc/zcat.1
+++ b/doc/zcat.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.37.1.
-.TH ZCAT "1" "January 2011" "Zcat (zutils) 0.9" "User Commands"
+.TH ZCAT "1" "March 2013" "Zcat (zutils) 1.0-rc6" "User Commands"
 .SH NAME
 Zcat \- decompress and concatenate files to standard output
 .SH SYNOPSIS
@@ -10,11 +10,12 @@ Zcat copies each given file ("\-" means standard input), to standard
 output. If any given file is compressed, its uncompressed content is
 used. If a given file does not exist, and its name does not end with one
 of the known extensions, zcat tries the compressed file names
-corresponding to the supported compressors. If no files are specified,
+corresponding to the supported formats. If no files are specified,
 data is read from standard input, decompressed if needed, and sent to
 standard output. Data read from standard input must be of the same type;
-all uncompressed or all compressed with the same compressor.
-The supported compressors are bzip2, gzip, lzip and xz.
+all uncompressed or all in the same compression format.
+.PP
+The supported formats are bzip2, gzip, lzip and xz.
 .PP
 Exit status is 0 if no errors occurred, 1 otherwise.
 .SH OPTIONS
@@ -26,16 +27,19 @@ display this help and exit
 output version information and exit
 .TP
 \fB\-A\fR, \fB\-\-show\-all\fR
-equivalent to `\-vET'
+equivalent to '\-vET'
 .TP
 \fB\-b\fR, \fB\-\-number\-nonblank\fR
 number nonblank output lines
 .TP
 \fB\-e\fR
-equivalent to `\-vE'
+equivalent to '\-vE'
 .TP
 \fB\-E\fR, \fB\-\-show\-ends\fR
-display `$' at end of each line
+display '$' at end of each line
+.TP
+\fB\-\-format=\fR<fmt>
+force given format (bz2, gz, lz, xz)
 .TP
 \fB\-n\fR, \fB\-\-number\fR
 number all output lines
@@ -50,13 +54,13 @@ operate recursively on directories
 never more than one single blank line
 .TP
 \fB\-t\fR
-equivalent to `\-vT'
+equivalent to '\-vT'
 .TP
 \fB\-T\fR, \fB\-\-show\-tabs\fR
-display TAB characters as `^I'
+display TAB characters as '^I'
 .TP
 \fB\-v\fR, \fB\-\-show\-nonprinting\fR
-use `^' and `M\-' notation, except for LF and TAB
+use '^' and 'M\-' notation, except for LF and TAB
 .TP
 \fB\-\-verbose\fR
 verbose mode (show error messages)
@@ -65,7 +69,7 @@ Report bugs to zutils\-bug@nongnu.org
 .br
 Zutils home page: http://www.nongnu.org/zutils/zutils.html
 .SH COPYRIGHT
-Copyright \(co 2011 Antonio Diaz Diaz.
+Copyright \(co 2013 Antonio Diaz Diaz.
 License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
 .br
 This is free software: you are free to change and redistribute it.
diff --git a/doc/zcmp.1 b/doc/zcmp.1
index 37ac57f..9b1d510 100644
--- a/doc/zcmp.1
+++ b/doc/zcmp.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.37.1.
-.TH ZCMP "1" "January 2011" "Zcmp (zutils) 0.9" "User Commands"
+.TH ZCMP "1" "March 2013" "Zcmp (zutils) 1.0-rc6" "User Commands"
 .SH NAME
 Zcmp \- decompress and compare two files byte by byte
 .SH SYNOPSIS
@@ -11,7 +11,8 @@ differ, tells the first byte and line number where they differ. Bytes
 and lines are numbered starting with 1. If any given file is compressed,
 its uncompressed content is used. Compressed files are uncompressed on
 the fly; no temporary files are created.
-The supported compressors are bzip2, gzip, lzip and xz.
+.PP
+The supported formats are bzip2, gzip, lzip and xz.
 .PP
 Compares <file1> to <file2>. If <file2> is omitted zcmp tries the
 following:
@@ -35,6 +36,9 @@ output version information and exit
 \fB\-b\fR, \fB\-\-print\-bytes\fR
 print differing bytes
 .TP
+\fB\-\-format\fR=\fI[\fR<fmt1>][,<fmt2>]
+force given formats (bz2, gz, lz, xz)
+.TP
 \fB\-i\fR, \fB\-\-ignore\-initial=\fR<n>[,<n2>]
 ignore differences in the first <n> bytes
 .TP
@@ -60,7 +64,7 @@ Report bugs to zutils\-bug@nongnu.org
 .br
 Zutils home page: http://www.nongnu.org/zutils/zutils.html
 .SH COPYRIGHT
-Copyright \(co 2011 Antonio Diaz Diaz.
+Copyright \(co 2013 Antonio Diaz Diaz.
 License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
 .br
 This is free software: you are free to change and redistribute it.
diff --git a/doc/zdiff.1 b/doc/zdiff.1
index dc4ad49..65c9a84 100644
--- a/doc/zdiff.1
+++ b/doc/zdiff.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.37.1.
-.TH ZDIFF "1" "January 2011" "Zdiff (zutils) 0.9" "User Commands"
+.TH ZDIFF "1" "March 2013" "Zdiff (zutils) 1.0-rc6" "User Commands"
 .SH NAME
 Zdiff \- decompress and compare two files line by line
 .SH SYNOPSIS
@@ -11,7 +11,8 @@ differ, shows the differences line by line. If any given file is
 compressed, its uncompressed content is used. Zdiff is a front end to
 the diff program and has the limitation that messages from diff refer to
 temporary filenames instead of those specified.
-The supported compressors are bzip2, gzip, lzip and xz.
+.PP
+The supported formats are bzip2, gzip, lzip and xz.
 .PP
 Compares <file1> to <file2>. If <file2> is omitted zdiff tries the
 following:
@@ -53,6 +54,9 @@ try hard to find a smaller set of changes
 \fB\-E\fR, \fB\-\-ignore\-tab\-expansion\fR
 ignore changes due to tab expansion
 .TP
+\fB\-\-format\fR=\fI[\fR<fmt1>][,<fmt2>]
+force given formats (bz2, gz, lz, xz)
+.TP
 \fB\-i\fR, \fB\-\-ignore\-case\fR
 ignore case differences in file contents
 .TP
@@ -87,7 +91,7 @@ Report bugs to zutils\-bug@nongnu.org
 .br
 Zutils home page: http://www.nongnu.org/zutils/zutils.html
 .SH COPYRIGHT
-Copyright \(co 2011 Antonio Diaz Diaz.
+Copyright \(co 2013 Antonio Diaz Diaz.
 License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
 .br
 This is free software: you are free to change and redistribute it.
diff --git a/doc/zgrep.1 b/doc/zgrep.1
index 7bdfb1a..a56ace6 100644
--- a/doc/zgrep.1
+++ b/doc/zgrep.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.37.1.
-.TH ZGREP "1" "January 2011" "Zgrep (zutils) 0.9" "User Commands"
+.TH ZGREP "1" "March 2013" "Zgrep (zutils) 1.0-rc6" "User Commands"
 .SH NAME
 Zgrep \- search compressed files for a regular expression
 .SH SYNOPSIS
@@ -11,11 +11,12 @@ on any combination of compressed and non\-compressed files. If any given
 file is compressed, its uncompressed content is used. If a given file
 does not exist, and its name does not end with one of the known
 extensions, zgrep tries the compressed file names corresponding to the
-supported compressors. If no files are specified, data is read from
+supported formats. If no files are specified, data is read from
 standard input, decompressed if needed, and fed to grep. Data read from
 standard input must be of the same type; all uncompressed or all
-compressed with the same compressor.
-The supported compressors are bzip2, gzip, lzip and xz.
+in the same compression format.
+.PP
+The supported formats are bzip2, gzip, lzip and xz.
 .PP
 Exit status is 0 if match, 1 if no match, 2 if trouble.
 .SH OPTIONS
@@ -56,6 +57,9 @@ obtain patterns from <file>
 \fB\-F\fR, \fB\-\-fixed\-strings\fR
 <pattern> is a set of newline\-separated strings
 .TP
+\fB\-\-format=\fR<fmt>
+force given format (bz2, gz, lz, xz)
+.TP
 \fB\-h\fR, \fB\-\-no\-filename\fR
 suppress the prefixing filename on output
 .TP
@@ -108,7 +112,7 @@ Report bugs to zutils\-bug@nongnu.org
 .br
 Zutils home page: http://www.nongnu.org/zutils/zutils.html
 .SH COPYRIGHT
-Copyright \(co 2011 Antonio Diaz Diaz.
+Copyright \(co 2013 Antonio Diaz Diaz.
 License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
 .br
 This is free software: you are free to change and redistribute it.
diff --git a/doc/ztest.1 b/doc/ztest.1
index 616420b..74d7102 100644
--- a/doc/ztest.1
+++ b/doc/ztest.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.37.1.
-.TH ZTEST "1" "January 2011" "Ztest (zutils) 0.9" "User Commands"
+.TH ZTEST "1" "March 2013" "Ztest (zutils) 1.0-rc6" "User Commands"
 .SH NAME
 Ztest \- verify integrity of compressed files
 .SH SYNOPSIS
@@ -9,10 +9,16 @@ Ztest \- verify integrity of compressed files
 Ztest verifies the integrity of the specified compressed files.
 Non\-compressed files are ignored. If no files are specified, the
 integrity of compressed data read from standard input is verified. Data
-read from standard input must be all compressed with the same compressor.
-The supported compressors are bzip2, gzip, lzip and xz.
+read from standard input must be all in the same compression format.
 .PP
-Exit status is 2 if any compressed file is corrupt, 0 otherwise.
+The supported formats are bzip2, gzip, lzip and xz.
+.PP
+Note that some xz files lack integrity information, and therefore can't
+be verified as reliably as the other formats can.
+.PP
+Exit status is 0 if all compressed files verify OK, 1 if environmental
+problems (file not found, invalid flags, I/O errors, etc), 2 if any
+compressed file is corrupt or invalid.
 .SH OPTIONS
 .TP
 \fB\-h\fR, \fB\-\-help\fR
@@ -21,6 +27,9 @@ display this help and exit
 \fB\-V\fR, \fB\-\-version\fR
 output version information and exit
 .TP
+\fB\-\-format=\fR<fmt>
+force given format (bz2, gz, lz, xz)
+.TP
 \fB\-q\fR, \fB\-\-quiet\fR
 suppress all messages
 .TP
@@ -34,7 +43,7 @@ Report bugs to zutils\-bug@nongnu.org
 .br
 Zutils home page: http://www.nongnu.org/zutils/zutils.html
 .SH COPYRIGHT
-Copyright \(co 2011 Antonio Diaz Diaz.
+Copyright \(co 2013 Antonio Diaz Diaz.
 License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
 .br
 This is free software: you are free to change and redistribute it.
diff --git a/doc/zutils.info b/doc/zutils.info
index 24f9bf4..9c27308 100644
--- a/doc/zutils.info
+++ b/doc/zutils.info
@@ -12,7 +12,7 @@ File: zutils.info,  Node: Top,  Next: Introduction,  Up: (dir)
 Zutils Manual
 *************
 
-This manual is for Zutils (version 0.9, 11 January 2011).
+This manual is for Zutils (version 1.0-rc6, 15 March 2013).
 
 * Menu:
 
@@ -26,7 +26,7 @@ This manual is for Zutils (version 0.9, 11 January 2011).
 * Concept Index::       Index of concepts
 
 
-   Copyright (C) 2008, 2009, 2010, 2011 Antonio Diaz Diaz.
+   Copyright (C) 2008, 2009, 2010, 2011, 2012, 2013 Antonio Diaz Diaz.
 
    This manual is free documentation: you have unlimited permission to
 copy, distribute and modify it.
@@ -41,12 +41,17 @@ Zutils is a collection of utilities able to deal with any combination of
 compressed and non-compressed files transparently. If any given file,
 including standard input, is compressed, its uncompressed content is
 used. Compressed files are decompressed on the fly; no temporary files
-are created. These utilities are not wrapper scripts but safer and more
-efficient C++ programs. In particular the `--recursive' option is very
-efficient in those utilities supporting it.
+are created.
+
+   These utilities are not wrapper scripts but safer and more efficient
+C++ programs. In particular the `--recursive' option is very efficient
+in those utilities supporting it.
 
 The provided utilities are zcat, zcmp, zdiff, zgrep and ztest.
-The supported compressors are bzip2, gzip, lzip and xz.
+The supported formats are bzip2, gzip, lzip and xz.
+
+   Zcat, zcmp, zdiff, and zgrep are improved replacements for the shell
+scripts provided with GNU gzip. Ztest is unique to zutils.
 
 
    Numbers given as arguments to options (positions, sizes) may be
@@ -74,10 +79,12 @@ Zcat copies each given file (`-' means standard input), to standard
 output. If any given file is compressed, its uncompressed content is
 used. If a given file does not exist, and its name does not end with one
 of the known extensions, zcat tries the compressed file names
-corresponding to the supported compressors. If no files are specified,
-data is read from standard input, decompressed if needed, and sent to
-standard output. Data read from standard input must be of the same type;
-all uncompressed or all compressed with the same compressor.
+corresponding to the supported formats.
+
+   If no files are specified, data is read from standard input,
+decompressed if needed, and sent to standard output. Data read from
+standard input must be of the same type; all uncompressed or all in the
+same compression format.
 
    The format for running zcat is:
 
@@ -111,6 +118,11 @@ Exit status is 0 if no errors occurred, 1 otherwise.
 `--show-ends'
      Print a `$' after the end of each line.
 
+`--format=FMT'
+     Force the given compression format. Valid values for FMT are
+     `bz2', `gz', `lz' and `xz'. If this option is used, the exact file
+     name must be given. Other names won't be tried.
+
 `-n'
 `--number'
      Number all output lines, starting with 1. The line count is
@@ -161,13 +173,18 @@ fly; no temporary files are created.
 
      zcmp [OPTIONS] FILE1 [FILE2]
 
-Compares FILE1 to FILE2. If FILE2 is omitted zcmp tries the following:
-If FILE1 is compressed, compares FILE1 to the file with the
-corresponding decompressed file name (removes the extension from FILE1).
-If FILE1 is not compressed, compares FILE1 to the uncompressed contents
-of FILE1.[bz2|gz|lz|xz] (the first one that is found).
-If no suitable file is found, compares FILE1 to data read from standard
-input.
+This compares FILE1 to FILE2. If FILE2 is omitted zcmp tries the
+following:
+
+  1. If FILE1 is compressed, compares FILE1 to the file with the
+     corresponding decompressed file name (removes the extension from
+     FILE1).
+
+  2. If FILE1 is not compressed, compares FILE1 to the uncompressed
+     contents of FILE1.[bz2|gz|lz|xz] (the first one that is found).
+
+  3. If no suitable file is found, compares FILE1 to data read from
+     standard input.
 
 An exit status of 0 means no differences were found, 1 means some
 differences were found, and 2 means trouble.
@@ -188,6 +205,14 @@ differences were found, and 2 means trouble.
      a letter, and precede bytes larger than 127 with `M-' (which stands
      for "meta").
 
+`--format=[FMT1][,FMT2]'
+     Force the given compression formats. Any of FMT1 or FMT2 may be
+     omitted and the corresponding format will be automatically
+     detected.  Valid values for FMT are `bz2', `gz', `lz' and `xz'. If
+     at least one format is specified with this option, the exact file
+     names of both FILE1 and FILE2 must be given.  Other names won't be
+     tried.
+
 `-i SIZE'
 `--ignore-initial=SIZE'
      Ignore any differences in the first SIZE bytes of the input files.
@@ -231,13 +256,18 @@ temporary filenames instead of those specified.
 
      zdiff [OPTIONS] FILE1 [FILE2]
 
-Compares FILE1 to FILE2. If FILE2 is omitted zdiff tries the following:
-If FILE1 is compressed, compares FILE1 to the file with the
-corresponding decompressed file name (removes the extension from FILE1).
-If FILE1 is not compressed, compares FILE1 to the uncompressed contents
-of FILE1.[bz2|gz|lz|xz] (the first one that is found).
-If no suitable file is found, compares FILE1 to data read from standard
-input.
+This compares FILE1 to FILE2. If FILE2 is omitted zdiff tries the
+following:
+
+  1. If FILE1 is compressed, compares FILE1 to the file with the
+     corresponding decompressed file name (removes the extension from
+     FILE1).
+
+  2. If FILE1 is not compressed, compares FILE1 to the uncompressed
+     contents of FILE1.[bz2|gz|lz|xz] (the first one that is found).
+
+  3. If no suitable file is found, compares FILE1 to data read from
+     standard input.
 
 An exit status of 0 means no differences were found, 1 means some
 differences were found, and 2 means trouble.
@@ -279,6 +309,14 @@ differences were found, and 2 means trouble.
 `--ignore-tab-expansion'
      Ignore changes due to tab expansion.
 
+`--format=[FMT1][,FMT2]'
+     Force the given compression formats. Any of FMT1 or FMT2 may be
+     omitted and the corresponding format will be automatically
+     detected.  Valid values for FMT are `bz2', `gz', `lz' and `xz'. If
+     at least one format is specified with this option, the exact file
+     names of both FILE1 and FILE2 must be given.  Other names won't be
+     tried.
+
 `-i'
 `--ignore-case'
      Ignore case differences in file contents.
@@ -326,10 +364,12 @@ on any combination of compressed and non-compressed files. If any given
 file is compressed, its uncompressed content is used. If a given file
 does not exist, and its name does not end with one of the known
 extensions, zgrep tries the compressed file names corresponding to the
-supported compressors. If no files are specified, data is read from
-standard input, decompressed if needed, and fed to grep. Data read from
-standard input must be of the same type; all uncompressed or all
-compressed with the same compressor.
+supported formats.
+
+   If no files are specified, data is read from standard input,
+decompressed if needed, and fed to grep. Data read from standard input
+must be of the same type; all uncompressed or all in the same
+compression format.
 
    The format for running zgrep is:
 
@@ -387,9 +427,15 @@ matches were found, and 2 means trouble.
 `--fixed-strings'
      Treat PATTERN as a set of newline-separated strings.
 
+`--format=FMT'
+     Force the given compression format. Valid values for FMT are
+     `bz2', `gz', `lz' and `xz'. If this option is used, the exact file
+     name must be given. Other names won't be tried.
+
 `-h'
 `--no-filename'
-     Suppress the prefixing filename on output.
+     Suppress the prefixing of filenames on output when multiple files
+     are searched.
 
 `-H'
 `--with-filename'
@@ -459,16 +505,18 @@ File: zutils.info,  Node: Ztest,  Next: Problems,  Prev: Zgrep,  Up: Top
 Ztest verifies the integrity of the specified compressed files.
 Non-compressed files are ignored. If no files are specified, the
 integrity of compressed data read from standard input is verified. Data
-read from standard input must be all compressed with the same
-compressor.
+read from standard input must be all in the same compression format.
+
+   Note that some xz files lack integrity information, and therefore
+can't be verified as reliably as the other formats can.
 
    The format for running ztest is:
 
      ztest [OPTIONS] [FILES]
 
-The exit status is 0 if all files verify OK, 1 for environmental
-problems (file not found, invalid flags, I/O errors, etc), 2 to indicate
-a corrupt or invalid input file.
+The exit status is 0 if all compressed files verify OK, 1 if
+environmental problems (file not found, invalid flags, I/O errors, etc),
+2 if any compressed file is corrupt or invalid.
 
    Ztest supports the following options:
 
@@ -480,6 +528,11 @@ a corrupt or invalid input file.
 `--version'
      Print the version number of ztest on the standard output and exit.
 
+`--format=FMT'
+     Force the given compression format. Valid values for FMT are
+     `bz2', `gz', `lz' and `xz'. If this option is used, all files not
+     in the given format will fail.
+
 `-q'
 `--quiet'
      Quiet operation. Suppress all messages.
@@ -531,13 +584,18 @@ Concept Index
 
 Tag Table:
 Node: Top224
-Node: Introduction992
-Node: Zcat2447
-Node: Zcmp4331
-Node: Zdiff6388
-Node: Zgrep8625
-Node: Ztest11392
-Node: Problems12475
-Node: Concept Index13004
+Node: Introduction1006
+Node: Zcat2593
+Node: Zcmp4679
+Node: Zdiff7165
+Node: Zgrep9831
+Node: Ztest12842
+Node: Problems14246
+Node: Concept Index14775
 
 End Tag Table
+
+
+Local Variables:
+coding: iso-8859-15
+End:
diff --git a/doc/zutils.texinfo b/doc/zutils.texinfo
index b847830..af1fd90 100644
--- a/doc/zutils.texinfo
+++ b/doc/zutils.texinfo
@@ -1,12 +1,13 @@
 \input texinfo @c -*-texinfo-*-
 @c %**start of header
 @setfilename zutils.info
+@documentencoding ISO-8859-15
 @settitle Zutils Manual
 @finalout
 @c %**end of header
 
-@set UPDATED 11 January 2011
-@set VERSION 0.9
+@set UPDATED 15 March 2013
+@set VERSION 1.0-rc6
 
 @dircategory Data Compression
 @direntry
@@ -45,7 +46,8 @@ This manual is for Zutils (version @value{VERSION}, @value{UPDATED}).
 @end menu
 
 @sp 1
-Copyright @copyright{} 2008, 2009, 2010, 2011 Antonio Diaz Diaz.
+Copyright @copyright{} 2008, 2009, 2010, 2011, 2012, 2013
+Antonio Diaz Diaz.
 
 This manual is free documentation: you have unlimited permission
 to copy, distribute and modify it.
@@ -59,13 +61,18 @@ Zutils is a collection of utilities able to deal with any combination of
 compressed and non-compressed files transparently. If any given file,
 including standard input, is compressed, its uncompressed content is
 used. Compressed files are decompressed on the fly; no temporary files
-are created. These utilities are not wrapper scripts but safer and more
-efficient C++ programs. In particular the @samp{--recursive} option is
-very efficient in those utilities supporting it.
+are created.
+
+These utilities are not wrapper scripts but safer and more efficient C++
+programs. In particular the @samp{--recursive} option is very efficient
+in those utilities supporting it.
 
 @noindent
 The provided utilities are zcat, zcmp, zdiff, zgrep and ztest.@*
-The supported compressors are bzip2, gzip, lzip and xz.
+The supported formats are bzip2, gzip, lzip and xz.
+
+Zcat, zcmp, zdiff, and zgrep are improved replacements for the shell
+scripts provided with GNU gzip. Ztest is unique to zutils.
 
 @sp 1
 Numbers given as arguments to options (positions, sizes) may be followed
@@ -94,10 +101,12 @@ Zcat copies each given file (@samp{-} means standard input), to standard
 output. If any given file is compressed, its uncompressed content is
 used. If a given file does not exist, and its name does not end with one
 of the known extensions, zcat tries the compressed file names
-corresponding to the supported compressors. If no files are specified,
-data is read from standard input, decompressed if needed, and sent to
-standard output. Data read from standard input must be of the same type;
-all uncompressed or all compressed with the same compressor.
+corresponding to the supported formats.
+
+If no files are specified, data is read from standard input,
+decompressed if needed, and sent to standard output. Data read from
+standard input must be of the same type; all uncompressed or all in the
+same compression format.
 
 The format for running zcat is:
 
@@ -135,6 +144,11 @@ Equivalent to @samp{-vE}.
 @itemx --show-ends
 Print a @samp{$} after the end of each line.
 
+@item --format=@var{fmt}
+Force the given compression format. Valid values for @var{fmt} are
+@samp{bz2}, @samp{gz}, @samp{lz} and @samp{xz}. If this option is used,
+the exact file name must be given. Other names won't be tried.
+
 @item -n
 @itemx --number
 Number all output lines, starting with 1. The line count is unlimited.
@@ -187,16 +201,22 @@ zcmp [@var{options}] @var{file1} [@var{file2}]
 @end example
 
 @noindent
-Compares @var{file1} to @var{file2}. If @var{file2} is omitted zcmp
-tries the following:@*
+This compares @var{file1} to @var{file2}. If @var{file2} is omitted zcmp
+tries the following:
+
+@enumerate
+@item
 If @var{file1} is compressed, compares @var{file1} to the file with the
 corresponding decompressed file name (removes the extension from
-@var{file1}).@*
+@var{file1}).
+@item
 If @var{file1} is not compressed, compares @var{file1} to the
 uncompressed contents of @var{file1}.[bz2|gz|lz|xz] (the first one that
-is found).@*
+is found).
+@item
 If no suitable file is found, compares @var{file1} to data read from
 standard input.
+@end enumerate
 
 @noindent
 An exit status of 0 means no differences were found, 1 means some
@@ -219,6 +239,14 @@ Print the differing bytes. Print control bytes as a @samp{^} followed by
 a letter, and precede bytes larger than 127 with @samp{M-} (which stands
 for "meta").
 
+@item --format=[@var{fmt1}][,@var{fmt2}]
+Force the given compression formats. Any of @var{fmt1} or @var{fmt2} may
+be omitted and the corresponding format will be automatically detected.
+Valid values for @var{fmt} are @samp{bz2}, @samp{gz}, @samp{lz} and
+@samp{xz}. If at least one format is specified with this option, the
+exact file names of both @var{file1} and @var{file2} must be given.
+Other names won't be tried.
+
 @item -i @var{size}
 @itemx --ignore-initial=@var{size}
 Ignore any differences in the first @var{size} bytes of the input files.
@@ -265,16 +293,22 @@ zdiff [@var{options}] @var{file1} [@var{file2}]
 @end example
 
 @noindent
-Compares @var{file1} to @var{file2}. If @var{file2} is omitted zdiff
-tries the following:@*
+This compares @var{file1} to @var{file2}. If @var{file2} is omitted
+zdiff tries the following:
+
+@enumerate
+@item
 If @var{file1} is compressed, compares @var{file1} to the file with the
 corresponding decompressed file name (removes the extension from
-@var{file1}).@*
+@var{file1}).
+@item
 If @var{file1} is not compressed, compares @var{file1} to the
 uncompressed contents of @var{file1}.[bz2|gz|lz|xz] (the first one that
-is found).@*
+is found).
+@item
 If no suitable file is found, compares @var{file1} to data read from
 standard input.
+@end enumerate
 
 @noindent
 An exit status of 0 means no differences were found, 1 means some
@@ -318,6 +352,14 @@ Try hard to find a smaller set of changes.
 @itemx --ignore-tab-expansion
 Ignore changes due to tab expansion.
 
+@item --format=[@var{fmt1}][,@var{fmt2}]
+Force the given compression formats. Any of @var{fmt1} or @var{fmt2} may
+be omitted and the corresponding format will be automatically detected.
+Valid values for @var{fmt} are @samp{bz2}, @samp{gz}, @samp{lz} and
+@samp{xz}. If at least one format is specified with this option, the
+exact file names of both @var{file1} and @var{file2} must be given.
+Other names won't be tried.
+
 @item -i
 @itemx --ignore-case
 Ignore case differences in file contents.
@@ -365,10 +407,12 @@ on any combination of compressed and non-compressed files. If any given
 file is compressed, its uncompressed content is used. If a given file
 does not exist, and its name does not end with one of the known
 extensions, zgrep tries the compressed file names corresponding to the
-supported compressors. If no files are specified, data is read from
-standard input, decompressed if needed, and fed to grep. Data read from
-standard input must be of the same type; all uncompressed or all
-compressed with the same compressor.
+supported formats.
+
+If no files are specified, data is read from standard input,
+decompressed if needed, and fed to grep. Data read from standard input
+must be of the same type; all uncompressed or all in the same
+compression format.
 
 The format for running zgrep is:
 
@@ -430,9 +474,15 @@ Obtain patterns from @var{file}, one per line.
 @itemx --fixed-strings
 Treat @var{pattern} as a set of newline-separated strings.
 
+@item --format=@var{fmt}
+Force the given compression format. Valid values for @var{fmt} are
+@samp{bz2}, @samp{gz}, @samp{lz} and @samp{xz}. If this option is used,
+the exact file name must be given. Other names won't be tried.
+
 @item -h
 @itemx --no-filename
-Suppress the prefixing filename on output.
+Suppress the prefixing of filenames on output when multiple files are
+searched.
 
 @item -H
 @itemx --with-filename
@@ -502,7 +552,10 @@ Match only whole lines.
 Ztest verifies the integrity of the specified compressed files.
 Non-compressed files are ignored. If no files are specified, the
 integrity of compressed data read from standard input is verified. Data
-read from standard input must be all compressed with the same compressor.
+read from standard input must be all in the same compression format.
+
+Note that some xz files lack integrity information, and therefore can't
+be verified as reliably as the other formats can.
 
 The format for running ztest is:
 
@@ -511,9 +564,9 @@ ztest [@var{options}] [@var{files}]
 @end example
 
 @noindent
-The exit status is 0 if all files verify OK, 1 for environmental
-problems (file not found, invalid flags, I/O errors, etc), 2 to indicate
-a corrupt or invalid input file.
+The exit status is 0 if all compressed files verify OK, 1 if
+environmental problems (file not found, invalid flags, I/O errors, etc),
+2 if any compressed file is corrupt or invalid.
 
 Ztest supports the following options:
 
@@ -526,6 +579,11 @@ Print an informative help message describing the options and exit.
 @itemx --version
 Print the version number of ztest on the standard output and exit.
 
+@item --format=@var{fmt}
+Force the given compression format. Valid values for @var{fmt} are
+@samp{bz2}, @samp{gz}, @samp{lz} and @samp{xz}. If this option is used,
+all files not in the given format will fail.
+
 @item -q
 @itemx --quiet
 Quiet operation. Suppress all messages.