This section describes some of the more commonly used environment variables. Many of these variables might already be in your user profile. As previously mentioned, your user profile file is located in your home directory.
To view hidden (“dot”) files, use the -la options of the ls command.
CDPATH – Specifies the directories to be searched when a unique directory name is typed without a full path name.
LOGNAME – Defines your login name. The default for this variable is automatically set to the login name specified in the passwd database as part of the login process. See System Administration Guide: Basic Administration for information on the passwd database.
PATH – Lists, in order, the directories that the system searches to find a program to run when you type a command. If the appropriate directory is not in the search path, you have to type it or else type the complete path name when you enter a command.
The default for this variable is automatically defined and set as specified in your user profile file as part of the login process.
PS1 – Defines your command prompt. The default prompt for the Bourne, Bourne Again, and Korn shells is the dollar sign ($). The default prompt for the C, TC, and Z shells is the percent sign (%). The default prompt for root in either shell is the pound sign (#).
TERMINFO – Specifies the path name for an unsupported terminal that has been added to the terminfo database. You do not need to set this variable for default terminals in this database. See System Administration Guide: Advanced Administration for information on the terminfo database.
TERM – Defines the terminal you're currently using. When you run an editor, the system searches for a file with the same name as the definition of this variable. The system first searches the path (if any) referenced by the
TERMINFO variable, and then the default directory, /usr/share/lib/terminfo, to determine the characteristics of the terminal. If a definition is not found in either location, the terminal is identified as “dumb.”