When you type a command on the command line, you’re basically telling the shell to run an executable file with the given name. In Linux, these executable programs like
file and others, usually live inside several different directories on your system. Any file with executable permissions stored in these directories can be run from any location. The most common directories that hold executable programs are
But how does the shell knows, what directories to search for executable programs? Does the shell search through the whole filesystem?
The answer is simple. When you type a command, the shell searches through all directories specified in the user
$PATH variable for an executable file of that name.
This article shows how to add directories to your
$PATH in Linux systems.
$PATH in Linux
$PATH environmental variable is a colon-delimited list of directories that tells the shell which directories to search for executable files.
To check what directories are in your
$PATH, you can use either the
The output will look something like this:
If you have two executable files sharing the same name located in two different directories, the shell will run the file that is in the directory that comes first in the
Adding a Directory to your
There are situations where you may want to add other directories to the
$PATH variable. For example, some programs may be installed in different locations, or you may want to have a dedicated directory for your personal scrips, but be able to run them without specifying the absolute path to the executable files. To do this, you simply need to add the directory to your
Let’s say you have a directory called
bin located in your Home directory in which you keep your shell scripts. To add the directory to your
$PATH type in:
export command will export the modified variable to the shell child process environments.
You can now run your scripts by typing the executable script name without needing to specify the full path to the file.
However, this change is only temporary and valid only in the current shell session.
To make the change permanent, you need to define the
$PATH variable in the shell configuration files. In most Linux distributions when you start a new session, environment variables are read from the following files:
- Global shell specific configuration files such as
/etc/profile. Use this file if you want the new directory to be added to all system users
- Per-user shell specific configuration files. For example, if you are using Bash, you can set the
$PATHvariable in the
~/.bashrcfile. If you are using Zsh the file name is
In this example, we’ll set the variable in the
~/.bashrc file. Open the file with your text editor and add the following line at the end of it:
Save the file and load the new
$PATH into the current shell session using the
To confirm that the directory was successfully added, print the value of your
$PATH by typing:
Adding new directories to your user or global
$PATH variable is pretty simple. This allows you to execute commands and scripts stored on nonstandard locations without needing to type the full path to the executable.
The same instructions apply for any Linux distribution, including Ubuntu, CentOS, RHEL, Debian, and Linux Mint.
Feel free to leave a comment if you have any questions.