Using Multiple Commands
So far you've seen how to use the command line interface (CLI) prompt of the shell to enter commands and view the command results. The key to shell scripts is the ability to enter multiple commands and process the results from each command, even possibly passing the results of one command to another. The shell allows you to chain commands together into a single step.
If you want to run two commands together, you can enter them on the same prompt line, separated with a semicolon:
$ date ; who
Mon Feb 21 15:36:09 EST 2014
Christine tty2 2014-02-21 15:26
Samantha tty3 2014-02-21 15:26
Timothy tty1 2014-02-21 15:26
user tty7 2014-02-19 14:03 (:0)
user pts/0 2014-02-21 15:21 (:0.0)
$
Congratulations, you just wrote a shell script! This simple script uses just two bash
shell commands. The date
command runs first, displaying the current date and time, followed by the output of the who
command, showing who is currently...