Bash-Beginners-Guide

Bash Guide for Beginners
command > file 2>&1
11.3. Summary
Functions provide an easy way of grouping commands that you need to execute repetitively. When a function
is running, the positional parameters are changed to those of the function. When it stops, they are reset to
those of the calling program. Functions are like mini-scripts, and just like a script, they generate exit or return
codes.
While this was a short chapter, it contains important knowledge needed for achieving the ultimate state of
laziness that is the typical goal of any system administrator.
11.4. Exercises
Here are some useful things you can do using functions:
1.
Add a function to your ~/.bashrc config file that automates the printing of man pages. The result
should be that you type something like printman , upon which the first appropriate man
page rolls out of your printer. Check using a pseudo printer device for testing purposes.
As an extra, build in a possibility for the user to supply the section number of the man page he or she
wants to print.
2. Create a subdirectory in your home directory in which you can store function definitions. Put a couple
of functions in that directory. Useful functions might be, amongs others, that you have the same
commands as on DOS or a commercial UNIX when working with Linux, or vice versa. These
functions should then be imported in your shell environment when ~/.bashrc is read.
Chapter 11. Functions 136