What is the Linux PATH environment variable?

Linux PATH environment variable is a parameter that determines which directories the Shell will search for commands or programs. Its content is composed of a bunch of directories, separated by colons ":". When a Linux command is executed, Linux will search for the executable file of the command in sequence according to the directory included in the PATH environment variable. Once found, it will be executed normally; otherwise, it will prompt that the command cannot be found.

#The operating environment of this tutorial: linux7.3 system, Dell G3 computer.

What are environment variables

Linux is a multi-user operating system, and each user has his or her own dedicated operating environment. The environment used by the user is defined by a series of variables, which are called environment variables. System environment variables are usually in uppercase letters.

Each user can modify their own environment variables as needed to meet their own usage requirements. Common environment variables are as follows:

Shell#23##HOSTNAMEhostLANGUAGELanguageMAILStorage directory11(1)Normal##lsCommand results

Serial number	Variable	Description
##1	##PATH## has decided that	will In which directories should you look for commands or programs? This variable is a variable## that often needs to be modified in daily use.
TERM	Specify system Terminal
##SHELL	Current UserShell Type	4
HOME	Current userHome directory	5
LOGNAME	The current user’s login name	6
USER	##CurrentUsername	7
HISTSIZE	##History CommandNumber of records	##8
refers to the name of		9
	Related environment variables, multi-languagecan modify this environment variable	10
## of the current user #mail		##PS1
Basic Prompt:	rootThe user is #(2)	The user is $ ##12 PS2
Attached prompt, the default is >	##13	LS_COLORS
ColorDisplay	<p><strong><span style="font-size: 18px;">Linux PATH environment variable</span></strong></p> <p>The contents of the PATH environment variable in Linux are composed of a bunch of directories, with colons ":" between each directory. separated. When executing a Linux command, Linux will search for the executable file of the command in sequence according to the directory included in the PATH environment variable. Once found, it will be executed normally; otherwise, it will prompt that the command cannot be found. </p> <p><strong>Explanation</strong></p> <p>That is to say, when the user enters an external command in the shell command line interface, the shell must search the system to find the corresponding program. The PATH environment variable defines the directory where commands and programs are searched. </p> <p>If the location of the command or program is not included in the PATH variable, the shell cannot find it without using an absolute path. If you want to execute a program anywhere in the virtual directory structure, add the directory where the program is located to the PATH environment variable, or put the program / link (ln) to a directory that already exists in the PATH . </p> <p><strong>Check the PATH environment variable</strong></p> <p>Enter </p><div class="code" style="position:relative; padding:0px; margin:0px;"><pre class='brush:php;toolbar:false;'>echo $PATH</pre><div class="contentsignin">Copy after login</div></div><p> on the command line or enter: </p><div class="code" style="position:relative; padding:0px; margin:0px;"><pre class='brush:php;toolbar:false;'>export</pre><div class="contentsignin">Copy after login</div></div><p>Example 1: Check the environment variable echo $PATH</p> <p><img src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/image/239/989/585/1675669813143578.png" class="lazy" title="1675669813143578.png" alt="What is the Linux PATH environment variable?"></p> <p>Example 2: View environment variables export</p> <p><img src="https://img.php.cn/upload/image/461/383/629/167566981828202What%20is%20the%20Linux%20PATH%20environment%20variable?" title="167566981828202What is the Linux PATH environment variable?" alt="What is the Linux PATH environment variable?"></p>##Related recommendations: "<p>Linux Video Tutorial<a href="http://www.php.cn/course/list/33.html" target="_blank">》</a></p>

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