Shell Programming and Scripting

Hello frnds...

I m asking a general question... thought I never faced and used this (PS3) variable... or may be i m not aware of this...

I know very well about the unix prompt string variables PS1,PS2,PS4.

but please tell me what is the use of PS3 and where it's used.
I didnt find anything satisfactory thing by googling...

thanks,,
Anchal.

PS3->Prompt string in select loops

thanks pt14 for replying..
but the same thing i got on the net... isnt clear for me...

can u please explain this.... preferably by example... that actually whre PS3 come into the picture...

thanks again...

Run this to find out:

Code:

#!/bin/ksh

quitstr=Exit
choices="a b c d $quitstr"
PS3="Enter your choice: "
select opt in $choices ; do
        [ "${opt}" = "${quitstr}" ] && break
        [ "x${opt}" = "x" ] && continue
        echo "You chose : $opt"
done

HTH

very thanks rikxik.. got it.

Consider the script:
select i in jan feb mar exit
do
case $i in
jan) echo "Jan";;
feb) echo "feb";;
mar) echo "mar";;
exit) exit;;
*) echo "invalid entry";;
esac
done

Run the script when you have not set PS3:
1) jan
2) feb
3) mar
1
Jan


When you have set PS3
PS3="Select a month: "
1) jan
2) feb
3) mar
Select the item number: 1
Jan


Hope this helps