Regex in Unix

Shell Programming and Scripting
1

user can enter Yes or yes or YES and its captured in variable say var

if [ $var == [Yy][Ee][Ss] ]
then
  #do something
elif [ $var == [Nn] [Oo] ]
then
  #do something

I think you got what i want to do. I can use "OR" logic in "if" statement like if ["YES"] || [ "yes"] but do not want to use OR , Is there any way it can be done?

2

hi,
try this.

echo "Enter Yes or No: "
read a

while true
do
 case $a in
	[Yy]* ) 
 	echo "yes is entered"
 	break;;
	[Nn]* ) 
	echo "no is entered"
 	break;;
 	* ) echo "Please enter Yes or No ";;
 esac
done
3

You can use typset to force uppercase (or lowercase):

#typeset -u var
#var=yes
#echo $var
YES
1 Like
4

Here's an idea - you could convert user input to lower case and then compare it with "yes". Ditto with "no".

$
$ x="Yes"
$
$ echo $x | tr [A-Z] [a-z]
yes
$
$
$ x="YeS"
$
$ echo $x | tr [A-Z] [a-z]
yes
$
$
$ x="YES"
$
$ echo $x | tr [A-Z] [a-z]
yes
$
$

tyler_durden