How To Read and Set Environmental and Shell Variables on Linux

Environmental and shell variables are essential components of the Linux operating system. They are used to store important information, such as system paths and configuration settings, which are required by various applications and processes.

Reading Environmental Variables

You can read the value of an environmental variable by using the echo command followed by the name of the variable. For example:

echo $PATH

This will display the value of the PATH variable, which contains a list of directories that the system searches when looking for a command.

Setting Environmental Variables

You can set an environmental variable by using the export command followed by the name of the variable and its value. For example:

export MY_VAR="Hello World"

This will create a new environmental variable called MY_VAR with a value of Hello World.

Reading Shell Variables

Shell variables are similar to environmental variables, but they are specific to the current shell session. You can read the value of a shell variable by using the echo command followed by the name of the variable. For example:

echo $SHELL

This will display the value of the SHELL variable, which contains the path to the current shell executable.

Setting Shell Variables

You can set a shell variable by simply assigning a value to it. For example:

MY_VAR="Hello World"

This will create a new shell variable called MY_VAR with a value of Hello World.

Conclusion

Environmental and shell variables are important components of the Linux operating system. By knowing how to read and set these variables, you can customize your system and ensure that your applications and processes have access to the information they need.

Keywords: Linux, environmental variables, shell variables, tutorial, echo command, export command, system paths, configuration settings, shell session, shell executable.