How to set environment variables?

You can set environment variables in various ways depending on the operating system and the shell you are using. Here are some common methods:

In Unix/Linux (Bash Shell)

1. Temporary Environment Variable (only for the current session):

   export VARIABLE_NAME="value"

2. Persistent Environment Variable (across sessions):

   • Open your .bashrc or .bash_profile file:

     nano ~/.bashrc

   • Add the following line at the end of the file:

     export VARIABLE_NAME="value"

   • Save and exit the editor, then run:

     source ~/.bashrc

In Unix/Linux (Zsh Shell)

1. Temporary Environment Variable:

   export VARIABLE_NAME="value"

2. Persistent Environment Variable:

   • Open your .zshrc file:

     nano ~/.zshrc

   • Add the following line:

     export VARIABLE_NAME="value"

   • Save and exit, then run:

     source ~/.zshrc

In Windows (Command Prompt)

1. Temporary Environment Variable:

   set VARIABLE_NAME=value

2. Persistent Environment Variable:

   setx VARIABLE_NAME "value"

In Windows (PowerShell)

1. Temporary Environment Variable:

   $env:VARIABLE_NAME="value"

2. Persistent Environment Variable:

   [System.Environment]::SetEnvironmentVariable("VARIABLE_NAME", "value", "User")

Example

For example, to set a variable named MY_VAR with the value HelloWorld in a Bash shell, you would do:

export MY_VAR="HelloWorld"

To make it persistent, add the same line to your .bashrc or .bash_profile file and source it.