Translations by Robert Readman

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Introduction To The Command Line

Credits and License

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This document is made available under the Creative Commons ShareAlike 2.5 License (CC-BY-SA).

You are free to modify, extend, and improve the Ubuntu documentation source code under the terms of this license. All derivative works must be released under this license.

This documentation 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 AS DESCRIBED IN THE DISCLAIMER.

A copy of the license is available here: <ulink url="help:/kubuntu/copyright.html">Creative Commons ShareAlike License</ulink>.

2009

Ubuntu Documentation Project

Canonical Ltd. and members of the <placeholder-1/>

The Ubuntu Documentation Project

This document provides a brief description of the Linux command line. It is not a complete guide to the command line, but rather an introduction to complement <phrase>Kubuntu</phrase>'s graphical tools.

Introduction

man intro(1)

"Under Linux there are GUIs (graphical user interfaces), where you can point and click and drag, and hopefully get work done without first reading lots of documentation. The traditional Unix environment is a CLI (command line interface), where you type commands to tell the computer what to do. That is faster and more powerful, but requires finding out what the commands are." -- from <placeholder-1/>

This guide describes some basic GNU/Linux shell commands. It is not intended to be a complete guide to the command line, just an introduction to complement <phrase>Kubuntu</phrase>'s graphical tools.

All command names, file names or paths to directories will be shown using a <command>monospace font</command>.

The commands should be issued from a command prompt within a <application>Terminal</application> and will be shown as: <screen>command to type</screen>

<emphasis role="strong">Command Line Linux is case sensitive.</emphasis> User, user, and USER are each different and distinct in Linux.

Starting A Terminal

<phrase>Kubuntu</phrase>'s Terminal application is called <application>Konsole</application>, and is opened by going to <menuchoice><guimenu>Kickoff Application Launcher</guimenu><guisubmenu>Applications</guisubmenu><guisubmenu>System</guisubmenu><guimenuitem>Terminal (Konsole)</guimenuitem></menuchoice>.

<phrase>Kubuntu</phrase>'s terminal - Konsole

File and Directory Commands

pwd - print working directory

<application>Konsole</application> also displays this information in both the tab and title bar of its window.

The <command>pwd</command> command displays the directory where the user is currently located (<acronym>pwd</acronym> stands for <quote>print working directory</quote>). For example, typing <screen>pwd</screen> while in the <filename class="directory">Desktop</filename> will show <computeroutput>/home/[username]/Desktop</computeroutput>. <placeholder-1/>

cd - change directory

The <command>cd</command> command changes directories (<acronym>cd</acronym> stands for <quote>change directory</quote>). When a terminal window is opened, it will be located in the user's home directory. Moving around the file system requires the use of <command>cd</command>.

To navigate into the root directory, type: <screen>cd /</screen>

To navigate to the current user's home directory, type: <screen>cd</screen> or <screen>cd ~</screen>

The <command>~</command> character represents the current user's home directory. As shown above, <command>cd ~</command> is equivalent to <command>cd /home/username/</command>. However, when running a command as root (using <command>sudo</command>, for example), <command>~</command> points to <filename class="directory">/root</filename>. When running a <command>cd</command> command with <command>sudo</command>, the full path to the home directory must be given.

To navigate up one directory level, type: <screen>cd ..</screen>

To navigate up two directory levels, type: <screen>cd ../../</screen>

To navigate to the previous directory (go back), type: <screen>cd -</screen>

To navigate through multiple levels of directories at once, specify the full directory path. For example, type: <screen>cd /var/log</screen> to go directly to the <filename class="directory">/log</filename> subdirectory of <filename class="directory">/var/</filename>. For another example, typing: <screen>cd ~/Desktop</screen> moves to the <filename class="directory">Desktop</filename> subdirectory inside the current user's home directory.

ls - list files

The <command>ls</command> command outputs a list of the files in the current directory (<acronym>ls</acronym> is short for <quote>list</quote>). For example, typing <screen>ls ~</screen> will display the files that are in the current user's home directory.

Used with the <command>-l</command> option, <command>ls</command> outputs other information along with the filename, such as the permissions on the file, the file's owner, and more.

Used with the <command>-al</command> options, <command>ls</command> outputs the information associated with the <command>-l</command> option in addition to showing hidden files (<command>a</command> option).

touch - create empty file

The <command>touch</command> command is used either to change a file's access and modification timestamps or to create a new empty file. For example, <screen>touch foo</screen> will create a new empty file named <filename>foo</filename>. If <filename>foo</filename> is already a file, then using <command>touch</command> will update the timestamps on the file which will show the last time a file was <emphasis>touched</emphasis>.

mkdir - make directory

The <command>mkdir</command> command is used to create a new directory (<acronym>mkdir</acronym> stands for <quote>make directory</quote>). To create a new directory named <filename class="directory">foobar</filename>, type: <screen>mkdir foobar</screen>

cp - copy files or directories

The <command>cp</command> command makes a copy of a file or directory (<acronym>cp</acronym> is short for <quote>copy</quote>). To make an exact copy of <filename>foo</filename> and name it <filename>bar</filename>, type: <screen>cp foo bar</screen> To make an exact copy of the <filename class="directory">foo_dir</filename> directory and name it <filename class="directory">bar_dir</filename>, type: <screen>cp -r foo_dir bar_dir</screen>

mv - move files or directories

The <command>mv</command> command moves a file or directory to a different location or will rename a file or directory (<acronym>mv</acronym> is short for <quote>move</quote>). To rename the file <filename>foo</filename> to <filename>bar</filename>, type: <screen>mv foo bar</screen> To move the file <filename>foo</filename> into the current user's <filename class="directory">Desktop</filename> directory, type: <screen>mv foo ~/Desktop</screen> This will not rename <filename>foo</filename> to <filename>Desktop</filename> because <filename>foo</filename> is a file and <filename class="directory">Desktop</filename> is a directory.

rm - remove files or directories

The <command>rm</command> command is used to delete files and directories (<acronym>rm</acronym> is short for <quote>remove</quote>). To delete the file <filename>foo</filename> for the current directory, type: <screen>rm foo</screen>