Finding your way on a Linux System Part 1

Command-line is used basically in Linux. This is the communication means between the user and the system. It’s a very complex tool. Each command has its own key unique option, therefore documentation is key when working with a Linux system.

There are many methods to get help from the Linux command lines such as man, help, and info but are only a few we will focus on here.

Built-in Help

When started with the –help parameter, most commands display some brief instructions about their usage. Instructions from –help parameter is rather brief as compared to others.

$help

GNU bash, version 5.0.17(1)-release (x86_64-pc-linux-gnu)
These shell commands are defined internally.  Type `help' to see this list.
Type `help name' to find out more about the function `name'.
Use `info bash' to find out more about the shell in general.
Use `man -k' or `info' to find out more about commands not in this list.

Man pages

Most commands provide a manual page or a ‘man page’. This documentation comes with the software and can be accessed with the man command. For example, man mkdir

$ man mkdir

This command opens the man page for Mkdir. You can navigate through using up and down arrow keys. To exit the man page press q for quiet.

MKDIR(1)                         User Commands                        MKDIR(1)

NAME
       mkdir - make directories

SYNOPSIS
       mkdir [OPTION]... DIRECTORY...

DESCRIPTION
       Create the DIRECTORY(ies), if they do not already exist.

       Mandatory  arguments  to  long  options are mandatory for short options
       too.

       -m, --mode=MODE
              set file mode (as in chmod), not a=rwx - umask

       -p, --parents
              no error if existing, make parent directories as needed

       -v, --verbose
              print a message for each created directory

Info pages

The info pages are usually more detailed than the man pages and are formatted in hypertext, similar to web pages on the internet.

$ info mkdir
Next: mkfifo invocation,  Prev: ln invocation,  Up: Special file types

12.3 ‘mkdir’: Make directories
==============================

‘mkdir’ creates directories with the specified names.  Synopsis:

     mkdir [OPTION]... NAME...

   ‘mkdir’ creates each directory NAME in the order given.  It reports
an error if NAME already exists, unless the ‘-p’ option is given and
NAME is a directory.

   The program accepts the following options.  Also see *note Common
options::.

‘-m MODE’
‘--mode=MODE’
     Set the file permission bits of created directories to MODE, which
     uses the same syntax as in ‘chmod’ and uses ‘a=rwx’ (read, write
     and execute allowed for everyone) for the point of the departure.
     *Note File permissions::.
-----Info: (coreutils)mkdir invocation, 65 lines --Top--------------------------
Welcome to Info version 6.7.  Type H for help, h for tutorial.

Locating Files

The locate command

The locate command searches within the database and then outputs every name that matches a given string.

$ locate note

The find command

The find command is used to search for files in the directories. Find searches a directory tree recursively. It does not maintain the database as locate command. Find requires the path to search.

Next article we will explore directories and listing of files in Linux