command line argument

Shell Script To Create Files and Directories That Do Not Exist

in Academic, Decision Making, File-management last updated February 19, 2009

A UNIX / Linux / BSD BASH Shell Script To Create Files and Directories That Do Not Exist.

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 Find Largest Among 3 Integers (Numbers) Given As Arguments

in Academic, Decision Making, Shell Math last updated October 20, 2008

Shell code to find largest integer among the 3 integers given as arguments.

Shell Script To Read File Date – Last Access / Modification Time

in File-management last updated October 1, 2008

A shell script to display file date in following format:

+ Time of last access
+ Time of last modification
+ Time of last change

Shell script to echo the length of the given string as argument

in Academic, String Management last updated August 9, 2008

A shell script to find out the length of a sting given as a command line argument.

Shell Script To Display Last Five Lines Of The File

in Academic last updated April 12, 2008

Given the filename by the user as the input, write a shell script to display the last five lines of the file.

Shell Script

#!/bin/bash
# get filename
echo -n "Enter File Name : "
read fileName

# make sure file exits for reading
if [ ! -f $fileName ]; then
  echo "Filename $fileName does not exists"
  exit 1
fi

# display last five lines of the file using tail command
tail -5 $fileName

#!/bin/bash

# get filename

echo -n "Enter File Name : "

read fileName

# make sure file exits for reading

if [ ! -f $fileName ]; then

echo "Filename $fileName does not exists"

exit 1

# display last five lines of the file using tail command

tail -5 $fileName

Command Line Argument

You can read file name as command line argument:

#!/bin/bash
# get filename
fileName="$1"
# make sure command line arg provided 
if [ -z $1 ]; then
	echo "Syntax: $(basename $0) filename"
	exit 1
fi
# make sure file exits for reading
if [ ! -f $fileName ]; then
  echo "Filename $fileName does not exists"
  exit 1
fi
# ok display last five lines of the file using tail command
tail -5 $fileName

#!/bin/bash

# get filename

fileName="$1"

# make sure command line arg provided

if [ -z $1 ]; then

echo "Syntax: $(basename $0) filename"

exit 1

# make sure file exits for reading

if [ ! -f $fileName ]; then

echo "Filename $fileName does not exists"

exit 1

# ok display last five lines of the file using tail command

tail -5 $fileName

Shell Script Utility To Read a File Line By Line

in File-management last updated September 21, 2009

A bash shell script to read file line by line using shell read command and I/O operators.

Shell script to rename given file names to from uppercase to lowercase OR lowercase to uppercase

in File-management last updated April 9, 2008

#!/bin/bash
# 
# Shell script to rename given file names to from uppercase to 
# lowercase OR lowercase to uppercase
# 
# Copyright (C) 2005 nixCraft project.
#
# This script licensed under GNU GPL version 2.0 or above
#
# Support/FeedBack/comment :  http://cyberciti.biz/fb/
# -------------------------------------------------------------------
# To rename file uppercase to lowercase create sym link:
# ln -s /path/2upper /path/2lower
# -------------------------------------------------------------------------
# This script is part of nixCraft shell script collection (NSSC)
# Visit http://bash.cyberciti.biz/ for more information.
# -------------------------------------------------------------------------

FILES="$1"
ME="$(basename $0)"

# function to display message and exit with given exit code
function die(){
  echo -e "$1"
  exit $2
}

# exit if no command line argument given
[ "$FILES" == "" ] && die "Syntax: $ME {file-name}\nExamples:\n $ME xyz\n $ME \"*.jpg\"" 1 || :
# scan for all input file
for i in $FILES
do
   # see if upper to lower OR lower to upper by command name
   [ "$ME" == "2upper" ] && N="$(echo "$i" | tr [a-z] [A-Z])" ||  N="$(echo "$i" | tr [A-Z] [a-z])"
   # if source and dest file not the same then rename it  
   [ "$i" != "$N" ] &&  mv "$i" "$N" || :
done

#!/bin/bash

# Shell script to rename given file names to from uppercase to

# lowercase OR lowercase to uppercase

# This script licensed under GNU GPL version 2.0 or above

# Support/FeedBack/comment : http://cyberciti.biz/fb/

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

# To rename file uppercase to lowercase create sym link:

# ln -s /path/2upper /path/2lower

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

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

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

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

FILES="$1"

ME="$(basename $0)"

# function to display message and exit with given exit code

function die(){

echo -e "$1"

exit $2

}

# exit if no command line argument given

[ "$FILES" == "" ] && die "Syntax: $ME {file-name}\nExamples:\n $ME xyz\n $ME \"*.jpg\"" 1 || :

# scan for all input file

for i in $FILES

# see if upper to lower OR lower to upper by command name

[ "$ME" == "2upper" ] && N="$(echo "$i" | tr [a-z] [A-Z])" || N="$(echo "$i" | tr [A-Z] [a-z])"

# if source and dest file not the same then rename it

[ "$i" != "$N" ] && mv "$i" "$N" || :

done