case … esac command

Shell Script To Simulate a Simple Calculator

in Academic, Shell Math last updated October 20, 2008

Shell Program to simulate a simple calculator operations such as addition and multiplication.

Shell Script To Read IP Address ( Find Ip Address Script )

in Script last updated April 10, 2008

#!/bin/sh
# Shell script scripts to read ip address
# -------------------------------------------------------------------------
# Copyright (c) 2005 nixCraft project <http://cyberciti.biz/fb/>
# This script is licensed under GNU GPL version 2.0 or above
# -------------------------------------------------------------------------
# This script is part of nixCraft shell script collection (NSSC)
# Visit http://bash.cyberciti.biz/ for more information.
# -------------------------------------------------------------------------
# Get OS name
OS=`uname`
IO="" # store IP
case $OS in
   Linux) IP=`ifconfig  | grep 'inet addr:'| grep -v '127.0.0.1' | cut -d: -f2 | awk '{ print $1}'`;;
   FreeBSD|OpenBSD) IP=`ifconfig  | grep -E 'inet.[0-9]' | grep -v '127.0.0.1' | awk '{ print $2}'` ;;
   SunOS) IP=`ifconfig -a | grep inet | grep -v '127.0.0.1' | awk '{ print $2} '` ;;
   *) IP="Unknown";;
esac
echo "$IP"

#!/bin/sh

# Shell script scripts to read ip address

# -------------------------------------------------------------------------

# This script is licensed under GNU GPL version 2.0 or above

# -------------------------------------------------------------------------

# This script is part of nixCraft shell script collection (NSSC)

# Visit http://bash.cyberciti.biz/ for more information.

# -------------------------------------------------------------------------

# Get OS name

OS=`uname`

IO="" # store IP

case $OS in

Linux) IP=`ifconfig | grep 'inet addr:'| grep -v '127.0.0.1' | cut -d: -f2 | awk '{ print $1}'`;;

FreeBSD|OpenBSD) IP=`ifconfig | grep -E 'inet.[0-9]' | grep -v '127.0.0.1' | awk '{ print $2}'` ;;

SunOS) IP=`ifconfig -a | grep inet | grep -v '127.0.0.1' | awk '{ print $2} '` ;;

*) IP="Unknown";;

esac

echo "$IP"

Shell script to read a number and write the number in words

in Decision Making last updated April 5, 2008

Script logic is as follows:

a) First read number into a shell variable

b) Next get one digit at a time

c) Use simple case control structure and loop to find digit equivalent in words

Sample script to convert numbers into equivalent words

#!/bin/bash
# Shell script to read a number and write the number in words. Use case
# control structure. For example 12 should be print as one two
# -------------------------------------------------------------------------
# Copyright (c) 2005 nixCraft project <http://cyberciti.biz/fb/>
# This script is licensed under GNU GPL version 2.0 or above
# -------------------------------------------------------------------------
# This script is part of nixCraft shell script collection (NSSC)
# Visit http://bash.cyberciti.biz/ for more information.
# -------------------------------------------------------------------------

echo -n "Enter number : "
read n

len=$(echo $n | wc -c)
len=$(( $len - 1 ))

echo "Your number $n in words : "
for (( i=1; i<=$len; i++ ))
do
   # get one digit at a time
    digit=$(echo $n | cut -c $i)
   # use case control structure to find digit equivalent in words 
    case $digit in
        0) echo -n "zero " ;;
        1) echo -n "one " ;;
        2) echo -n "two " ;;
        3) echo -n "three " ;;
        4) echo -n "four " ;;
        5) echo -n "five " ;;
        6) echo -n "six " ;;
        7) echo -n "seven " ;;
        8) echo -n "eight " ;;
        9) echo -n "nine " ;;
    esac	
done

# just print new line
echo ""

#!/bin/bash

# Shell script to read a number and write the number in words. Use case

# control structure. For example 12 should be print as one two

# -------------------------------------------------------------------------

# This script is licensed under GNU GPL version 2.0 or above

# -------------------------------------------------------------------------

# This script is part of nixCraft shell script collection (NSSC)

# Visit http://bash.cyberciti.biz/ for more information.

# -------------------------------------------------------------------------

echo -n "Enter number : "

read n

len=$(echo $n | wc -c)

len=$(( $len - 1 ))

echo "Your number $n in words : "

for (( i=1; i<=$len; i++ ))

# get one digit at a time

digit=$(echo $n | cut -c $i)

# use case control structure to find digit equivalent in words

case $digit in

0) echo -n "zero " ;;

1) echo -n "one " ;;

2) echo -n "two " ;;

3) echo -n "three " ;;

4) echo -n "four " ;;

5) echo -n "five " ;;

6) echo -n "six " ;;

7) echo -n "seven " ;;

8) echo -n "eight " ;;

9) echo -n "nine " ;;

esac

done

# just print new line

echo ""

Menu Driven Shell Script

in Decision Making last updated April 5, 2008

Explains how to write a menu driven Shell script, which has following options:
1. Contents of /etc/passwd
2. List of users currently logged
3. Present handling directory (working directory)
4. Exit

Take action as per selected option

#!/bin/bash
# A menu driven Shell script which has following options
# Contents of /etc/passwd
# List of users currently logged
# Prsent handling directory
# Exit
# As per option do the job
# -----------------------------------------------
# Copyright (c) 2005 nixCraft project <http://cyberciti.biz/fb/>
# This script is licensed under GNU GPL version 2.0 or above
# -------------------------------------------------------------------------
# This script is part of nixCraft shell script collection (NSSC)
# Visit http://bash.cyberciti.biz/ for more information.
# -------------------------------------------------------------------------

while :
do
 clear
 echo "   M A I N - M E N U"
 echo "1. Contents of /etc/passwd"
 echo "2. List of users currently logged"
 echo "3. Prsent handling directory"
 echo "4. Exit"
 echo -n "Please enter option [1 - 4]"
 read opt
 case $opt in
  1) echo "************ Conents of /etc/passwd *************";
     more /etc/passwd;;
  2) echo "*********** List of users currently logged";
     who | more;;
  3) echo "You are in $(pwd) directory";   
     echo "Press [enter] key to continue. . .";
     read enterKey;;
  4) echo "Bye $USER";
     exit 1;;
  *) echo "$opt is an invaild option. Please select option between 1-4 only";
     echo "Press [enter] key to continue. . .";
     read enterKey;;
esac
done

#!/bin/bash

# A menu driven Shell script which has following options

# Contents of /etc/passwd

# List of users currently logged

# Prsent handling directory

# Exit

# As per option do the job

# -----------------------------------------------

# This script is licensed under GNU GPL version 2.0 or above

# -------------------------------------------------------------------------

# This script is part of nixCraft shell script collection (NSSC)

# Visit http://bash.cyberciti.biz/ for more information.

# -------------------------------------------------------------------------

while :

clear

echo " M A I N - M E N U"

echo "1. Contents of /etc/passwd"

echo "2. List of users currently logged"

echo "3. Prsent handling directory"

echo "4. Exit"

echo -n "Please enter option [1 - 4]"

read opt

case $opt in

1) echo "************ Conents of /etc/passwd *************";

more /etc/passwd;;

2) echo "*********** List of users currently logged";

who | more;;

3) echo "You are in $(pwd) directory";

echo "Press [enter] key to continue. . .";

read enterKey;;

4) echo "Bye $USER";

exit 1;;

*) echo "$opt is an invaild option. Please select option between 1-4 only";

echo "Press [enter] key to continue. . .";

read enterKey;;

esac

done