reg exp matching problem

[tecknick]

I am trying to test some user input in a program.

example.....

    $input = '700.00,,'

    if ($input !~ /\d+\.\d+/)
        {
        print "invalid";
        }

I am only want input of the form 700.00 not
700.00,,

I could write .....

if( $input != '700.00')
{
print "invalid";
}

But I never know what the user will input.

How do I overcome this problem using reg exp's?

Thanks

 

[chazoid]

this will match 700.00 or .5 etc..
the ^ and $ anchor the ends to the beginning and end of the string, so you're saying there can be nothing but digits on either side of the decimal point.
If you want it to match a number before the decimal point just change \d* back to \d+

if ($input !~ /^\d*\.\d+$/){
    print "invalid";
}else{
    print "valid";
}