Advanced Bash−Scripting Guide

Advanced Bash−Scripting Guide
Example 12−13. Checking words in a list for validity
#!/bin/bash
# lookup: Does a dictionary lookup on each word in a data file.
file=words.data # Data file from which to read words to test.
echo
while [ "$word" != end ] # Last word in data file.
do
read word # From data file, because of redirection at end of loop.
look $word > /dev/null # Don't want to display lines in dictionary file.
lookup=$? # Exit status of 'look' command.
if [ "$lookup" −eq 0 ]
then
echo "\"$word\" is valid."
else
echo "\"$word\" is invalid."
fi
done /dev/null
then echo "\"$word\" is valid."
else echo "\"$word\" is invalid."
fi
done