Bash Programming

[uglyboy]

Where do I learn Bash Programming from ?

Any source where I can download source code or script to learn ?

I'm reading "Learning Bash" , but its not helping me

[Irithori]

Hi and welcome

Is this what you are reading?
Learning the bash Shell: Unix Shell Programming (In a Nutshell (O'Reilly)): Cameron Newham: 9780596009656: Amazon.com: Books

In what area or specific case do you need help?

[uglyboy]

Okay, I'm looking @ 1 file.

shell file

#display main ticketing menu
display_menu()
{
  # Called by run_menu
  echo
  echo "-- Theatre Self-service Ticketing --"
  echo -n "1. "
  echo -e '\E[1;32;40mList all Movies and Show time\E[0m'
  echo -n "2. "
  echo -e '\E[1;32;40mDisplay theatre鈥檚 seat \E[0m'
  echo -n "q. "
  echo -e '\E[1;31;47mQuit\E[0m'
	
  echo -en "Enter your selection: "
}

# List out available movies
list_movies()
{
	# Called by run_menu
	
	old_IFS=$IFS 
	IFS=$'\n'
	print_movie_header
	for LINE in `sed -e 's/Yes/Ticket Available/g' -e 's/No/SOLD OUT/g' movielist.txt`  
	do
		print_movie $LINE
	done
  IFS=$old_IFS 
}
	
# Output header for movie listing
# Catered for both numbered and non-numbered list
print_movie_header()
{
	echo -e '\E[1;32;40m'
	if [ $# == "1" ];then
		echo -n "   "
	fi
	echo -n -e 'Movie Title'
  set_colwidth 'Movie Title' 25
	echo -n -e 'Show Time\t'
	if [ $# == "1" ];then
		echo -n -e "\t"
	fi
	echo -n 'Vacancy'
	echo -e '\E[0m'
}

# Set the width of column
# $1 is the text in the column 
# and $2 is the intended column width
set_colwidth()
{
	STRING=$1
	LENGTH=${#STRING}

	for (( i=$LENGTH; i<=$2; i++))
	do 
		echo -n " "
	done 

}

# Output movie entry
print_movie()
{
	TIME=`echo $1 | cut -f1 -d ","`
	TITLE=`echo $1 | cut -f2 -d ","`
	AVAILABLE=`echo $1 | cut -f3 -d ","` 

	echo -n -e $TITLE
	set_colwidth $TITLE 25
	echo -n -e $TIME '\t'
  echo $AVAILABLE
}


# Hint2
# Get current seating arrangement of 
# selected movie from seating.txt
movie_data()
{
	COUNT=1
	old_IFS=$IFS 
	IFS=$'\n'
	for LINE in `cat seating.txt`  
	do
		if test $1 -eq $COUNT
			then
				display_seats $LINE $2

		fi
		THEATER[$COUNT]=$LINE
		let COUNT=COUNT+1
		
	done
  IFS=$old_IFS 	
}

# Mark occupied seat with a X and
# seats selected by user with a red X
mark_seat()
{
	# Called by display_seats
	
	if [ $(echo "$1" | grep -c "$2$3") -gt 0 ]
	then
			echo -n "X" 
		  set_colwidth "" 5
	elif [ $(echo "$4" | grep -c "$2$3") -gt 0 ]
	then
			echo -en '\E[1;31mX\E[0m'
		  set_colwidth "" 5
	else
			set_colwidth "" 6 
	fi
}

# Print out theater's seating arrangement
display_seats()
{
	COL=5
	ROW=4
	echo

	echo "---------------------------------------"
	echo -e '\E[1;34;47m----------------SCREEN-----------------\E[0m'
	echo "---------------------------------------"
	for (( x=0; x<=$ROW; x++))
	do 
	echo -n "$x" | tr "0" " "
		for (( j=0; j<=$COL; j++))
		do 
			if [ $x == "0" ]
			then
				echo -n $j | tr "012345" " ABCDE"
				set_colwidth "" 5
			else
				CURR_COL=$(echo $j | tr "12345" "ABCDE")
				if [ $j == "0" ]
				then
					set_colwidth "" 6
				else
					mark_seat $1 $CURR_COL $x $2
				fi
			fi
	done 
  echo ""
	done
	echo "---------------------------------------"
}


# Select and book seat manually
select_seat()
{
	# Called by run_menu
	
	COUNT=0
	echo
	echo "-- Select A Seat Manually --"
	echo
	old_IFS=$IFS 
	IFS=$'\n'
	print_movie_header "numbered"
	for LINE in `sed -e 's/Yes/Ticket Available/g' -e 's/No/SOLD OUT/g' movielist.txt `;do
		let COUNT=COUNT+1
		echo -n "$COUNT. "
		print_movie $LINE
	done
	IFS=$old_IFS 
	echo
	
	# Select movie to book
	echo -en "Select Movie To Book (Enter 1 to ${COUNT}): "
	read NUM
	NUMERIC=0
	while [ "$NUMERIC" != "1" ];do
		for (( x=$COUNT; x>=1; x--))
		do
			if [ $NUM == "$x" ];then
				NUMERIC=1
			fi
		done

		if [ "$NUMERIC" != "1" ];then
			echo -en "Invalid Movie Selected, Try Again (Enter 1 to ${COUNT}): "
			read NUM
		fi
	done

	movie_data $NUM
	echo
	old_IFS=$IFS 
	IFS=$'\n'
	
	 
	echo
}

# Main menu navigation
run_menu()
{
	i=-1
  while [ "$i" != "q" ]; do
		display_menu
		read i
		i=`echo $i | tr '[A-Z]' '[a-z]'`

		case "$i" in 
	  	"1")
			list_movies
			;;
		"2")
			select_seat
			;;
		"q")
			echo "GoodBye, Have A Nice Day"
			exit 0
			;;
		*)
			echo "Unrecognised Input."
			;;
		esac
  done
}


#----------------------------------------------#
# ---------PROGRAM SCRIPT START HERE---------- #
#----------------------------------------------#

if [ ! -f movielist.txt ]; then
  echo "Error: Movie list is not available"
fi


run_menu

movielist.txt

1300 – 2Oct,The Social Network,No
1300 – 2Oct,The Town,Yes
1700 – 2Oct,Paranormal Activity 2,Yes
1900 – 2Oct,You Again,Yes
2100 – 2Oct,Kamui,Yes

seating.txt

0;,A2,A3,A1,A7,A9
0;,E6,E7,E8

14;,A1,D4,C3,B3,A4,E4
15;,A1,D4,E2,C3,A2
15;,A1,B2,C3,D4,A4

Can anyone explain to me the shell ?

How do you create extra table in the heading

Movie Title Time Slot Availability (how to include Book Now )

How do you also align the data to fit the header

[uglyboy]

anyone or any book who can teach me how to use bash/

[watael]

hi,

Advanced Bash Scripting

and

RFC 1855 - Netiquette Guidelines

[uglyboy]

Can anyone willing to teach me , online tutoring ?

[atreyu]

Can anyone explain to me the shell ?

i believe that is beyond the constraints of a forum. You've got read what you can, absorb it, and apply it to the code that you attempt. Follow tutorials and perform the examples they provide. You will get it, just stick with it.

How do you create extra table in the heading

How do you also align the data to fit the header

For these types of formatting issues, you ought to use printf. It is a Bash shell built-in function, and possibly also a more capable binary (/bin/printf). Here's an example:

#!/bin/bash
menus=(colA colB colC colD)
values=('foo' 'bar' 'really long value' 'meh')

printf "%-8s"   ${menus[0]}
printf "%-8s"   ${menus[1]}
printf "%-20s"  "${menus[2]}"
printf "%s\n" ${menus[3]}

printf "%-8s"   ${values[0]}
printf "%-8s"   ${values[1]}
printf "%-20s"  "${values[2]}"
printf "%s\n" ${values[3]}

The "%s" is simply the string you are printing. The "%-8s" means to left justify text, to the 8th character. Similar with %-20s. You can also right justify, and a bunch of other stuff with printf.

[uglyboy]

print_movie_header()
{
	echo -e '\E[1;32;40m'     #colour highlight
	if [ $# == "1" ];then
		echo -n "   "
	fi
	echo -n -e 'Movie Title'          #movie title appears with the length of 25 char
  set_colwidth 'Movie Title' 25
	echo -n -e 'Show Time\t'
	if [ $# == "1" ];then
		echo -n -e "\t"
	fi
	echo -n 'Vacancy'              #vacancy
	echo -e '\E[0m'                   #end of highlight
}

# Set the width of column
# $1 is the text in the column 
# and $2 is the intended column width
set_colwidth()
{
	STRING=$1
	LENGTH=${#STRING}

	for (( i=$LENGTH; i<=$2; i++))           #S2 refers to ??? Let us say I want more values
	do 
		echo -n " "
	done 

}

# Output movie entry
print_movie()
{
	TIME=`echo $1 | cut -f1 -d ","`
	TITLE=`echo $1 | cut -f2 -d ","`
	AVAILABLE=`echo $1 | cut -f3 -d ","` 

	echo -n -e $TITLE
	set_colwidth $TITLE 25
	echo -n -e $TIME '\t'
  echo $AVAILABLE
}

Right now, it shows


Movie Title Timing Availability
Bla Bla -------------- 1500 ---------- YES / Sold Out #because of the sed function

It happens like that when I try to have 4 information under header
Header1 ------------Header2-----------Header3-----------Header4
Bla1------------- ---- Bla 2 ---------------Bla3
Bla4

[Cancerous]

Just look where there's only something declared 3 times instead of 4.

print_movie()
{
	TIME=`echo $1 | cut -f1 -d ","`
	TITLE=`echo $1 | cut -f2 -d ","`
	AVAILABLE=`echo $1 | cut -f3 -d ","` 

	echo -n -e $TITLE
	set_colwidth $TITLE 25
	echo -n -e $TIME '\t'
  echo $AVAILABLE
}

See, you're only cutting 3 headings instead of 4.

[uglyboy]

Just look where there's only something declared 3 times instead of 4.

print_movie()
{
	TIME=`echo $1 | cut -f1 -d ","`
	TITLE=`echo $1 | cut -f2 -d ","`
	AVAILABLE=`echo $1 | cut -f3 -d ","` 
           #*   BOOKNOW =`echo $1 | cut -f4 -d ","`

	echo -n -e $TITLE
	set_colwidth $TITLE 25
	echo -n -e $TIME '\t'
                echo $AVAILABLE
#* echo -n -e $BOOKNOW

}

See, you're only cutting 3 headings instead of 4.

This isn't the one I did with the editing, I'm saying can I just do this.

It displays Time First instead of Title first, I want to know why