Is there any reference or documentation for Linux commands?



When you come across a new word and don't know what it means, you will start looking for its meaning in a dictionary. But what if you have  just heard about a new Linux command and have absolutely no idea what the command does? Where will you look for a reference or documentation to the command?

Most Unix/*nix commands comes with their own documentation. These documents are available in the form of man / info pages and can be easily accessed from a shell


man pages

man pages is short form for manual pages. They are an interface to the on-line reference manuals in most Unix/*nix operating systems. The man page displays details of a command in several sections of simple ASCII text. Sections mostly comprises of NAME, SYNOPSIS, CONFIGURATION, DESCRIPTION, OPTIONS, EXIT STATUS, RETURN VALUE, ERRORS, ENVIRONMENT, FILES, VERSIONS, CONFORMING TO, NOTES, BUGS, EXAMPLE, AUTHORS, and SEE ALSO. In addition to the general commands there are man pages for System calls (functions provided by the kernel), Library calls(functions within program libraries) , Special Files, File formats and conventions(eg: /etc/passwd), Games, Miscellaneous, System administration commands (usually only for root) and Kernel routines [Non standard]

To display the man page, type
man command_name

Example
man man
will display the manual pages of man command as shown in the below screenshot

click to enlarge

info Pages

info pages are documentation system developed by GNU project to replace man pages, since they felt man was outdated. info is more descriptive than man and uses simpler markup language.

To display the info page, type 
info command_name

Example
info info
will display the info pages of info command as shown in the below screenshot

click to enlarge
 For more details on man and info commands check the respective man/info pages.

Comments

Post a Comment

Popular posts from this blog

Understanding awk command with examples

Image
Awk is a simple and powerful programming language used for processing text files. It is widely used by system administrators as a data manipulation, extraction and reporting tool. Awk treats every file as a sequence of records and by default each records are separated by a new line. Each record consist of one or more fields which are by default separated by a space. The syntax for awk command is
Read more

Understanding sed command with example -Part 1

sed is a *nix stream editor command with the ability to filter and transform input text files line by line. sed command works very well with awk command and they are used together by System Administrators to simplify day to day activities. The syntax for sed command is sed [options] commands <input-file> One thing that distinguishes sed from other editors are its ability to filter text in a pipeline. In this first of the two post series on sed we will cover 3 of the most often used commands. They are Print (p) command Quit (q) command Delete (d) command
Read more

How to install a Software in Linux

Image
After a fresh installation of a Linux distro your Laptop/PC/Server will contain almost all the essential software required for your system to work. But situations may arise where you have to depend upon additional software to perform your day to day activities. In this post we will look how to install a software in Linux.
Read more