Bash: how to read <enter> key

linmix · 12-02-2005, 03:56 PM

I have the following code snippet:

Code:

#!/bin/bash
question ()
{
echo '(y for yes, n for no, any other key to cancel)'
read tmp
if [ $tmp = "y" ]; then
 echo "you typed 'yes'"
elif [ $tmp = "n" ]; then
 clear
elif [ $tmp = "c" ]; then
 kill 0
else question
fi
}
question

If I run this script and instead of typing any 'normal' key press <enter> the I get an error message:

Code:

./test.sh: line 6: [: =: unary operator expected
./test.sh: line 8: [: =: unary operator expected
./test.sh: line 10: [: =: unary operator expected

How can I get the script to react to <enter> the same way as to any key (except of course 'y', 'n' and 'c')?

Andrew Benton · 12-02-2005, 04:11 PM

Try this

Code:

#!/bin/bash
question ()
{
echo '(y for yes, n for no, any other key to cancel)'
read tmp
case "$tmp" in
	y)
		echo "you typed 'yes'"
		;;
	n)
		clear
		;;
	c)
		kill 0
		;;
	*)
		question
esac
}
question

Berhanie · 12-02-2005, 04:14 PM

the point is to use quotes (so, "$tmp" instead of $tmp).

linmix · 12-02-2005, 04:38 PM

Thanks!!
it's the double quoting that does it (both in my snippet and in the 'case sollution suggested by Andrew.