Here’re some common environment variables:
| Variable | Description |
|---|---|
| PATH | This variable contains a colon (:)-separated list of directories in which your system looks for executable files. When you enter a command on terminal, the shell looks for the command in different directories mentioned in the $PATH variable. If the command is found, it executes. Otherwise, it returns with an error ‘command not found’. |
| LD_LIBRARY_PATH | LD_LIBRARY_PATH tells the dynamic link loader |
| USER | The username |
| HOME | Default path to the user’s home directory |
| EDITOR | Path to the program which edits the content of files |
| UID | User’s unique ID |
| TERM | Default terminal emulator |
| SHELL | Shell being used by the user |
You can find out more on Linux system ENVs at List of Environment Variables in Linux/Unix.