Tag: command line argument

Shell Script To Display Last Five Lines Of The File

in Categories 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

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

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

in Categories 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