# Day 1 4 #90DaysOfDevops

For day 14, I learnt how to manage user  environment variables.

The environment variables are important so as to get the most out of the Linux system also be adept at managing it for optimal performance and convenience. 

There are two types of variables: the shell and environment. The environment variables are in-built system wide variables that control how the system looks, acts and feels for the user while shell variables are typically listed in lower-cases and are only valid in the shell they are set in.

To view the default environment variables, the *env* command is entered into the terminal.

Variable’s values can be changed for a session. For example, to change the variable “HISTSIZE” which mostly has a value of 1000, the command *HISTSIZE=0* is entered. This changes the variable value to 0. To make such change permanent, the *export* command is used. It exports the new value from the current environment to the rest of the system until it is changed and exported again. *eport HISTSIZE* will set the HISTSIZE variable to 0 and export it to all environments.

One of the most variables in the environment is the PATH variable which controls where on the system the shell will look for commands such as cd, ls, cat. To view the directories stored in the PATH variable, the *echo $PATH* command is used. To add a new directory to the PATH, *PATH=$PATH:/root/newdirectory* is  used.

As a user, you can also create a variable by simply assigning a value to a variable that you name. It’s pretty straightforward. *MYNEWVARIABLE=”My name is Odunayo”*. This assigns a string to the variable *MYNEWVARIABLE*. Any new variable must also be exported so as to show up in new sessions.

These actions control how the working environment in linux looks, acts and feels. They can be changed to my personal taste . I played around and changed my PS1 variable to “Best Devops Engineer”. So that comes up when I open up my terminal hahah.

Cheers to Day 14 and cheers to many more days.