MacOS Environment Variables

• To display the list of currently set environment variables:

  printenv
  

• To display the value of any specific environment variable:

  echo $[variable name]
  

• To check the value of the PATH variable which stores a list of directories with executable files:

  echo $PATH
  

• To set a temporary environment variable:

  export [variable_name]=[variable_value]
  

• To add value to an existing environment variable:

  export [existing_variable_name]=[new_variable_value]:$[existing_variable_name]
  

  Example:

  export PATH=/Users/exec/tok:$PATH
  

• To set permanent environment variable
  1. Find the path to .bash_profile using:

     ~/.bash_profile
     

  2. Open the .bash_profile file with a text editor and add the new environmental variable to the end of the file using:

     export [variable_name]=[variable_value]
     

  3. Save the file and refresh the terminal using the below command or restart the terminal.

     source ~/.bash_profile
     

• To unset the environmental variable:

  unset [variable =_name]