validating variables (numeric)

pjd1 · #1 (**permalink**) 11-28-2006

Hi

I need to get a user to enter a number (an exchange rate) into a script. I have the following:

#!/bin/ksh
echo "Enter exchange rate:"
read EX_RATE
if [ -z "`echo \"$EX_RATE\" | tr -d \"[:digit:]\"`" ]
then
echo "Well done - only numeric here"
else
echo "Not so well done - there is NON numeric stuff here!"
fi

This works fine except when I try to enter a decimal number when it exits because the decimal point is obviously non-numeric. I have looked at the other class keywords and there is not one that covers decimals.

Can anyone help me out here?

thanks

Paul

vino · #2 (**permalink**) 11-28-2006

Quote:

Originally Posted by pjd1

if [ -z "`echo \"$EX_RATE\" | tr -d \"[:digit:]\"`" ]

Code:

if [ -z "`echo \"$EX_RATE\" | tr -d \"[0-9\.]\"`" ]

anbu23 · #3 (**permalink**) 11-28-2006

try this

Code:

echo "Enter exchange rate:"
read EX_RATE
if [ -n "`echo \"$EX_RATE\" | sed -n "/^[0-9.]\{1,\}$/p"`" ]
then
echo "Well done - only numeric here"
else
echo "Not so well done - there is NON numeric stuff here!"
fi

pjd1 · #4 (**permalink**) 11-28-2006

many thanks guys - both answers work a treat.

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