Black ZPhoenix blackzphoenix

My Understanding of Four Freedoms of Free Software !!!

Free Software refers to free as in freedom and that's what i too believe in !!!. A free software always should guarantee its users the essential four freedoms. The absence of at least any one of these freedoms means an application is not free software. I love the way the Free Freedoms of Free Software is expressed as - 100 ( in binary 4 ) Freedoms of Free Software.

 FREEDOM 0 :    `001 - USE`
 FREEDOM 1 :    `001 - STUDY`
 FREEDOM 2 :    `001 - SHARE`
 FREEDOM 3 :    `100 - IMPROVE`

SHELL SCRIPTING 0.0

Shell Scripting is a series of command/s stored in a plain text file and execute the text file instead of typing each command it is Shell Script.

Shell scripts can take input from a user or file and output them to the screen. Whenever one do the same task over and over again, using of shell script automates the repetitive task. Shell acts as a interface between Kernel and User.

	#first

	#!/bin/bash -x
	echo "Hello ${LOGNAME}"
	echo "Today is $(date)"
	echo "Users currently on the machine, and their processes:"

	#Second

	#!/bin/bash

	file 1: prog.sh
	#!/bin/bash
	var=$1
	case $var in
	maths)
	echo "In Engineering we have MATHS in 1st to 4th Sem..."
	;;
	phy)
	echo "Luckily or Sadly we have we have PHYSICS only for 1st or 2nd Sem..."
	;;

	#!/bin/bash
	NOW=$(date +"%a")
	case $NOW in
	Mon)
	echo "Full backup", $NOW;;
	Tue\|Wed\|Thu\|Fri)
	echo "Partial backup", $NOW;;
	Sat\|Sun)
	echo "No backup", $NOW;;
	*) ;;

	case $variable-name in case $variable-name in
	pattern1) pattern1\|pattern2\|pattern3)
	command1 command1
	... ...
	commandN commandN
	;; ;;
	pattern2) pattern4\|pattern5\|pattern6)
	command1 command1
	... ...
	commandN commandN

	$* : holds all command line parameters or arguments.
	$# : holds the number of positional parameters.
	$- : holds flags supplied to the shell.
	$? : holds the return value set by the previously executed command.
	$$ : holds the process number of the shell (current shell).
	$! : hold the process number of the last background command.
	$@ : holds all command line parameters or arguments.

	#!/bin/bash
	IFS="- "
	echo "* Display all Free Softwares names using \$@"
	echo "$@"
	echo

	echo "* Display all Free Softwares names using \$*"
	echo "$*"

	#!/bin/bash
	IFS="- "
	echo "The script name : $0"
	echo "The first argument to the script : $1"
	echo "The second argument to the script : $2"
	echo "The third argument to the script : $3"
	echo "The fourth argument to the script : $4"
	echo "The number of arguments passed to the script : $#"
	echo "* Display all free Softwares names usinng (\$@ version) : $@"
	echo

	#File Attributes Comparison are

	-a file : True if file exists.
	-b file : True if file exists and is a block special file.
	-c file : True if file exists and is a character special file.
	-d dir : True if file exists and is a directory.
	-e file : True if file exists.
	-f file : True if file exists and is a regular file.
	-g file : True if file exists and is set-group-id.
	-h file : True if file exists and is a symbolic link.