Noob: Created page with "Man pages, short for manual pages, are the standard form of documentation on a Unix-like system like Ubuntu 22.04. They provide detailed information about commands, system calls, library routines, and other components of the system. Man pages serve as a comprehensive reference, explaining the function of these components, their syntax, options, return values, and more. ==Accessing Man Pages== To access a man page for a specific command or program, use the man command f..."

2023-05-16T12:01:09Z

Created page with "Man pages, short for manual pages, are the standard form of documentation on a Unix-like system like Ubuntu 22.04. They provide detailed information about commands, system calls, library routines, and other components of the system. Man pages serve as a comprehensive reference, explaining the function of these components, their syntax, options, return values, and more. ==Accessing Man Pages== To access a man page for a specific command or program, use the man command f..."

New page

Man pages, short for manual pages, are the standard form of documentation on a Unix-like system like Ubuntu 22.04. They provide detailed information about commands, system calls, library routines, and other components of the system. Man pages serve as a comprehensive reference, explaining the function of these components, their syntax, options, return values, and more.

==Accessing Man Pages==

To access a man page for a specific command or program, use the man command followed by the name of the command or program. For example, to view the man page for the ls command, you would type:

<code>man ls</code>

This will bring up the man page for ls, which you can scroll through using the arrow keys. To exit, press '''q'''.

===Sections of Man Pages===

In Ubuntu 20.04 and other Linux distributions, man pages are typically stored in several directories under /usr/share/man. These directories are organized by sections, which are represented by numbers. The sections are as follows:

:* 1 '''User commands''' (Executable programs or shell commands)
:* 2 '''System calls''' (Functions provided by the kernel)
:* 3 '''Library calls''' (Functions within program libraries)
:* 4 '''Special files''' (Files found in /dev)
:* 5 '''File formats and conventions'''
:* 6 '''Games'''
:* 7 '''Miscellaneous''' (including macro packages and conventions)
:* 8 '''System administration commands''' (usually only for root)
:* 9 '''Kernel routines''' (Non-standard)

To access a man page in a specific section, you can specify the section number before the topic. For example, to access the system call read, you would type:

<code>man 2 read</code>

===Searching Man Pages===

If you're not sure what command or program you're looking for, you can search the man pages using the '''apropos''' command followed by a keyword. For example, to find commands related to "copy", you would type:

<code>apropos copy</code>

This will return a list of man pages related to the keyword "copy".
Conclusion

Man pages are a vital resource for users and administrators of Ubuntu 22.04, providing in-depth information on how to use and understand the system's various components. Understanding how to read and navigate man pages can greatly enhance your proficiency with the system.

Please note that man pages can sometimes be quite technical and may not be the easiest resource for beginners. Other resources, such as online tutorials, guides, and community forums, can often provide more accessible explanations and examples.

==Find the License of Man Pages==

The man pages in Ubuntu also use a variety of licenses, depending on the specific software and authors' preferences. As mentioned in my previous response, common licenses used for man pages in Ubuntu distributions include the GNU General Public License (GPL), GNU Lesser General Public License (LGPL), BSD License, MIT License, and Apache License.

To find the specific license for a particular man page in Ubuntu 20.04, you can look at the copyright information typically found at the bottom of the man page or consult the package documentation. Additionally, you can check the '''/usr/share/doc/<package_name>/copyright''' file, where '''<package_name>''' is the name of the package you are interested in.

Please note that some man pages may use other licenses or have custom licensing terms specified by the authors. Always refer to the documentation and copyright information for the specific man page or software package to determine its licensing terms.

===find the location of a specific man page===

To find the location of a specific man page, you can use the '''manpath''' command to display the search path for man pages, and the '''man -w <command>''' command to find the location of a specific man page. Replace '''<command>''' with the command or topic you are looking for. For example:

:* The '''manpath''' command will show the directories where man pages are stored
<code>manpath</code>

:* The '''man -w <package>''' command will display the location of the '''<package>''' command's man page.

Example:
:<code>man -w ls</code>

Will display the location of the '''ls''' command's man page. The output will show the full path to the man page file, such as '''/usr/share/man/man1/ls.1.gz'''

Please note that man pages are usually compressed using gzip, so the file extensions will often be .gz. To read the man page, use the man command, as it automatically decompresses the file:

<code>man ls</code>

The License of the '''ls''' man page is '''GPLv3+''' <br>
The "GPL-3+" means that the man page is licensed under the GNU General Public License version 3 or any later version.
<pre>
COPYRIGHT
Copyright © 2020 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

</pre>

==Example of finding the license of the '''mc''' man page==

: The '''mc''' "''midnight commander''" package is not installed on ubuntu by default:
<code>sudo apt install mc</code><br>

: Check the '''man mc''' page for license of the '''man''' for '''mc'''
<code>man mc</code>

<pre>
LICENSE
This program is distributed under the terms of the GNU General Public License as published by the Free Software Foundation. See the built-in help for details on the License and the lack of
warranty.
</pre>

The easiest way to find the license of a man page is to look for the license or copyright information within the man page itself, as you've done with the 'mc' man page. In some cases, the man page may not include the license information, and you will need to look for the copyright information in the package documentation instead.

To find the package documentation, you can check the '''/usr/share/doc/<package_name>/copyright''' file, where '''<package_name>''' is the name of the package you are interested in. For the 'mc' package, you can find the copyright file using the following command:

<code>cat /usr/share/doc/mc/copyright</code>

This command will display the copyright and license information for the 'mc' package, which should also cover the associated man page.

In the case of the 'mc' man page, the license information is already provided in the man page itself, stating that the program is distributed under the terms of the GNU General Public License.

===OutPut from <code>cat /usr/share/doc/mc/copyright</code>===

<pre>
Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Upstream-Name: Midnight Commander
Source: http://www.midnight-commander.org/downloads
Copyright: 1996-2021 Free Software Foundation
License: GPL-3+
Comment:
This package was debianized on Tue Apr 1 14:32:15 1997 by
Paul Seelig <pseelig@mail.uni-mainz.de>.

Files: *
Copyright: 1991-1992,1994-2021 Free Software Foundation
1996 andrey joukov <2:5020/337.13@fidonet.org>
2002 ARJ Software Russia
2003 Alexander Serkov <serkov@ukrpost.net>
1992-1998 Andrew Tridgell
1995 Ian Jackson <iwj10@cus.cam.ac.uk>
2008 Jacques Pelletier <jpelletier@ieee.org>
1996-1997 Joseph M. Hinkle <jhinkle@rockisland.com>
1998 John H Terpstra <jht@aquasoft.com.au>
1990-1998 Karl Auer
2005-2006 Leonard den Ottolander <leonard den ottolander nl>
1996-1998 Luke Kenneth Casson Leighton
1995-1996 Miguel de Icaza
2000-2001 Oskar Liljeblad <osk@hem.passagen.se>
1996 Paul Sheer
2003 Pavel Roskin
2002 Petr Kozelka <pkozelka@email.cz>
1999 Piotr Roszatycki <dexter@debian.org>
1995-1998 Samba-Team
2001 Walery Studennikov <despair@sama.ru>
1997-1998 the University of Minnesota
License: GPL-3+
Comment:
See list of authors and contributors in file AUTHORS
Note that all these authors assigned the copyright to FSF.

Files:
doc/doxygen-include.am
m4.include/dx_doxygen.m4
Copyright:
2004,2007 Oren Ben-Kiki
License: Apache-2.0

Files:
misc/syntax/nemerle.syntax
Copyright:
2004 the University of Wroclaw
License: BSD-3-Clause

Files:
misc/syntax/meson.syntax
Copyright:
2018 Vitold S
License: Expat

Files: debian/*
Copyright:
2002-2004 Adam Byrtek <alpha@debian.org>
2011 Andreas Tille <tille@debian.org>
2002 Colin Watson <cjwatson@debian.org>
2008-2015 Denis Briand <debian@denis-briand.fr>
2012-2021 Dmitry Smirnov <onlyjob@debian.org>
1997 Fernando Alegre <alegre@debian.org>
2004-2007 Ludovic Drolez <ldrolez@debian.org>
1999-2001 Martin Bialasinski <martinb@debian.org>
1999 Martin Bialasinski <mc@internet-treff.uni-koeln.de>
1998-1999 Michael Bramer <grisu@debian.org>
2008-2009 Patrick Winnertz <winnie@debian.org>
1998 Paul Seelig <pseelig@goofy.zdv.uni-mainz.de>
2004-2007 Stefano Melchior <stefano.melchior@openlabs.it>
1997 Vincent Renardias <vincent@waw.com>
2008-2010 Yury V. Zaytsev <yury@shurup.com>
License: GPL-2+

Files: src/vfs/smbfs/helpers/*
Copyright: 2011 Free Software Foundation
1992-1998 Andrew Tridgell
1995-1998 Samba-Team
1998 John H Terpstra <jht@aquasoft.com.au>
License: GPL-3+

Files:
m4.include/gnulib/fsusage.m4
m4.include/gnulib/sys_types_h.m4
m4.include/gnulib/windows-stat-inodes.m4
Copyright: 1997-2018 Free Software Foundation, Inc.
License: FSFULLR
This file is free software; the Free Software Foundation
gives unlimited permission to copy and/or distribute it,
with or without modifications, as long as this notice is preserved.

Files:
m4.include/ax_gcc_func_attribute.m4
Copyright: 2013 Gabriele Svelto <gabriele.svelto@gmail.com>
License: FSF-Install
Copying and distribution of this file, with or without modification, are
permitted in any medium without royalty provided the copyright notice and
this notice are preserved. This file is offered as-is, without any
warranty.

License: Apache-2.0
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
.
http://www.apache.org/licenses/LICENSE-2.0
.
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
․
On Debian systems, the complete text of the Apache License,
Version 2.0 can be found in "/usr/share/common-licenses/Apache-2.0".

License: BSD-3-Clause
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The name of the University may not be used to endorse or promote
products derived from this software without specific prior
written permission.
.
THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
NO EVENT SHALL THE UNIVERSITY BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

License: Expat
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
․
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
․
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

License: GPL-2+
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
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
․
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
․
On Debian systems, the complete text of the GNU General Public
License Version 2 can be found in "/usr/share/common-licenses/GPL-2".

License: GPL-3+
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
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
․
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
․
On Debian systems, the complete text of the GNU General Public
License Version 3 can be found in "/usr/share/common-licenses/GPL-3".
</pre>

Based on the information from the '''/usr/share/doc/mc/copyright''' file, the license for the Midnight Commander man page would be '''"GPL-3+"''', as indicated in the following section of the file:

<pre>
Files: *
Copyright: 1991-1992,1994-2021 Free Software Foundation
...
License: GPL-3+
</pre>

The "GPL-3+" means that the man page is licensed under the GNU General Public License version 3 or any later version.

==Export a 'man' page==

To export a man page in a readable format for copy and paste, you can use the man command with the '''-P''' flag to output the content to a specific pager, such as cat.

To export a man page in a readable format for copy and paste, you can use the man command with the -P flag to output the content to a specific pager, such as cat. Alternatively, you can use man with the col command to remove any formatting characters.

The '''-P''' flag in the man command allows you to specify a pager to view the manual page. A pager is a program that helps you read and navigate through text, such as less (default pager), more, or cat. To use the man command with the '''-P''' flag, follow this syntax:

<code>man -P <pager> <command></code>

Replace '''<pager>''' with the pager you want to use (e.g., cat, less, more) and '''<command>''' with the command you want to view the manual page for.

For example, if you want to view the ssh man page using the cat pager:

<code>man -P cat ssh</code>

This will output the ssh man page without any pagination, making it easy to copy and paste the content. Keep in mind that using cat as the pager will output the entire man page at once, which might be overwhelming for very long pages. To navigate through the content, you may want to use less or more instead.

'''Alternatively''', you can use man with the '''col''' command to remove any formatting characters.

For example, to view the ssh man page in a plain text format:

<code>man ssh | col -bx</code>

If you want to save the output to a file for easy copy and paste, you can redirect the output to a file:

<code>man ssh | col -bx > ssh_man_page.txt</code>

Now you can open the '''ssh_man_page.txt''' file with a text editor.

Ubuntu 22.04 Man Pages - Revision history