If the user logs on through the Bourne or the Korn Shell, the .profile file in his/her home directory is automatically executed.
That file contains commands to be executed upon logging in. Such commands are the setup of the PATH variable, and other environment variables (keyboard type, the prompt, etc.).
Some users like to know who is logged on when they get into UNIX. who could be added at the end of the file.
Examples could include:
PS=``Prompt>"
PRINTER=laserjet; export PRINTER
date
who