Working With Common Flow Constructs - Novell LINUX ENTERPRISE SERVER 11 - ADMINISTRATION Administration Manual

which prints:
Hello Tux
5.7 Working with Common Flow
Constructs
To control the flow of your script, a shell has while, if, for and case constructs.
5.7.1 The if Control Command
The if is used to check expressions. For example, the following code tests whether
the current user is Tux:
if test $USER = "tux" then
echo "Hello Tux."
else
echo "You are not Tux."
fi
The test expression can be as complex or simple as possible. The following expression
checks if the file foo.txt exists:
if test -e /tmp/foo.txt
then
echo "Found foo.txt"
fi
Find more useful expressions at
linux/docs/uniqlinuxfeatures/lsst/ch03sec02.html.
5.7.2 Creating Loops With The For
Command
The for loop allows you to execute commands to a list of entries. For example, the
following code prints some information about PNG files in the current directory:
for i in *.png; do
ls -l $i
done
http://www.cyberciti.biz/nixcraft/
Bash and Bash Scripts 51