UNIX for Advanced & Expert Users

#!/bin/sh
# check.sh
# This script takes two arguments -
# The first is the word you a looking for,
# and the second is the file you want to find
# the word in.
# Example: check.sh lamb haggis
# Will look for the word "lamb" in the file "haggis"
# This is to make sure there are exactly two arguments
# passed to the script. If not, it will give you a little hint...
# The "$#" counts the number of aguments, and -ne is the same
# as saying "not equal".
if [ "$#" -ne "2" ] ; then
     echo "Usage: "
     echo "`basename $0` {search string} {file} "
     exit 2
fi
[/b]# Right here, we check to make sure the file we are searching
# exists, and is a regular file. For more information on the -f
# statement, use the 'man test' command.[/b]
if [ -f "$2" ] ; then
# We don't actually want to see the results of the search,
# we only want to know if it was successful, so we send the
# output to /dev/null - to nowhere-land
grep "$1" $2 > /dev/null 
# The "$?" construct tells you the status of the last command.
# if $? is equal to zero, the command was successful, if it is any
# number other than 0, there was a problem
case $? in
     0) echo -e "\nThe word \"$1\" was found in the \"$2\" file! \n" ;;
     *) echo -e "\nThe word \"$1\" was NOT found in the \"$2\" file! \n" ;;
esac
exit 0
# This is what happens if the file did not exist (see above)
# This is our backup plan - it keeps grep from getting "stuck"
# if there is no file
else
echo "The \"$2\" file does not exist"
exit 2
fi