Common environment variables

Here is a list of common environment variables in Linux:

• USER – your current username.
• SHELL – the path to the current command shell (for example, /bin/bash).
• PWD – the current working directory.
• HOSTNAME – the hostname of the computer.
• HOME – your home directory.
• MAIL – the location of the user’s mail spool. Usually /var/spool/mail/USER.
• LANG – your current language.
• TZ – your time zone.
• PS1 – the default prompt in bash.
• TERM – the current terminal type (for example, xterm).
• DISPLAY – the display used by X. This variable is usually set to :0.0, which means the first display on the current computer.
• HISTFILESIZE – the maximum number of lines contained in the history file.
• EDITOR – the user’s preferred text editor.
• MANPATH – the list of directories to search for manual pages.
• OSTYPE – the type of operating system.