Townsville Linux Users Group

I wrote a simple address book in sh as an introduction to sh for people new to programming or shell scripting

Usage looks like this:

$ addressbook add
Enter data:
Some Person, Ph: 0412 345 678
Entry added
$ addressbook search person
Some Person, Ph: 0412 345 678
$


Code follows.


#!/usr/bin/env sh

DB_FILE=~/.addressbook.db

usage() {
echo "Usage: `basename $0` "
}

# must be at least one argument
if [ $# -eq 0 ]; then
usage
exit 1
fi

case "$1" in
"add")
# must be exactly one argument
if [ $# -ne 1 ]; then
usage
exit 1
fi

echo "Please enter name and number details on a single line, like 'Bob Rock, Mob: 0412 345 678'"
read input

# Write content to DB file
echo $input >> $DB_FILE
echo "Entry added"
;;
"search")
# Does the database exist?
if [ ! -e $DB_FILE ]; then
echo "Database doesn't exist. Please add some content first."
exit 1
fi

# If a search term wasn't specified on the command line, ask for one
if [ $# -eq 1 ]; then
echo "Enter a name: "
read searchterm

# The search term should be a single argument
elif [ $# -ne 2 ]; then
echo "Too many arguments."
usage
exit 1
else
searchterm=$2
fi

# Search the DB file for the specified string
grep -i "$searchterm" $DB_FILE | sort
if [ $? -ne 0 ]; then
echo "No results found."
fi
;;
*)
echo "Unknown argument $1"
usage
exit 1
;;
esac