How can you Test for bad number

Shell Programming and Scripting
1

Anyone know the code to test for bad numbers?

For example in ksh...
Want the user to input an integer, but they input characters.

read number
while (number = letter)
read number //until valid number is inputted

thx for any help!! :confused:

2

Use egrep to test...

read foo
echo "${foo}" | egrep "^[0-9]+$" >/dev/null 2>&1
if [ "$?" -eq "0" ]; then
  echo "Yay"
else
  echo "Nay"
fi

Cheers
ZB

3

This looks like a home work problem for me. Please read the Rules before posting.
Just a hint for your problem. Perform a arithmetic operation on your input. If it succeeds then numeric else it is non numeric.

4

Thanks Bob
works great :smiley: