Learning the UNIX Operating System, Fourth Edition

Customizing Your Account

As we saw earlier, your home directory may have a hidden file called .profile. If it doesn’t, there’ll probably be one or more files named .login, .cshrc, .tshrc, .bashrc, .bash_profile, or .bash_login. These file are shell setup files, the key to customizing your account. Shell setup files contain commands that are automatically executed when a new shell starts—especially when you log in.

Let’s take a look at these files. Go to your home directory, then use cat to display the file. Your .profile might look something like this:

PATH=/bin:/usr/bin:/usr/local/bin:
export PATH
/usr/games/fortune
date
umask 002
stty erase ^H intr ^C

A .login file might look something like this:

set path = (/bin /usr/bin /usr/local/bin .)
/usr/games
date
umask 002
stty erase ^H intr ^C

As you can see, these sample setup files contain commands to print a “fortune” and the date—just what happened earlier when we logged in! (/usr/games/fortune is a useless but entertaining program that prints a randomly selected saying from its collection. fortune isn’t available on all systems.)

But what are these other commands?

• The line with PATH= or set path = tells the shell which directories to search for UNIX commands. This saves you the trouble of typing the complete pathname for each program you run. (Notice that /usr/games isn’t part of the path, so we had to use the absolute pathname to get our daily dose of wisdom from the fortune command.)

• The umask command sets the default ...