Shell Programming and Scripting

Hi All,

I need to compare the string variable with input value which have more than one word which also should be case insensitive.

Code:

#!/bin/sh
echo "please choose your choice: "
read choice
if [ "$choice" = `echo "CASE TEST" | tr [:upper:] [:lower:]` ]
then echo "correct"
else
echo "wrong"
fi

but i am getting the output for first word only.
Someone plz help me how to compare if it is more than a word.

Thanks in advance for ur kind help.

Hello, kalai:

You need to double quote the command substitution to prevent tr's "case test" output from being split into multiple fields (the
= operator expects one operand on each side).

Also, do yourself a favor and get out of the habit of using `cmd args` for command subsitution. It's brittle and error prone (particularly once you start quoting and nesting). Chances are your shell supports the $(cmd arg) syntax, which is much easier to work with.

One last thing. You should quote each of the arguments to tr. The bracketed expressions are special to the shell (they're used in pattern matching) and there's a possibility that file name pattern matching could take place unintentionally.

In summary, my suggestions amount to changing a line in your code to the following:

Code:

if [ "$choice" = "$(echo "CASE TEST" | tr '[:upper:]' '[:lower:]')" ]

Regards and welcome to the forum,
Alister

Hi

i don't see the use of the following :

Code:

`echo "CASE TEST" | tr [:upper:] [:lower:]`

since could just be

"case test"

Maybe you could try something like:

Code:

if [ $(echo "$choice" | tr [:upper:] [:lower:]) = "case test" ]

Hi All,
I got the output what i want.

Code:

#!/bin/sh
echo "please choose your choice: "
read choice
b=$(echo "$choice" | tr [:upper:] [:lower:])
if [ "$b" = "case test" ]
then echo "correct"
else
echo "wrong"
fi

Still i dont know whats wrong if i compare directly within IF loop.

@Alister,
Hi

Thanks for your welcome and post . Initially i used bracketed expressions for that but i got some error.
but when i tried with the command args.. i dint find any error.
Thanks for your valuable suggestions.

@CTSGNB
Hi
Thanks for your valuable suggestions.