Perl正则表达式以匹配端口号的输入

Question

I would like to write a regular expression that would only accept valid input that would qualify as a port number. I want to only accept input for the characters 0-9 and no special characters. The number should not be longer than 5 characters.

I read user input using this method.

my $port_number = <>;

I know that the regular expression should look something like this.

^[0-9]*$

How do I combine the regular expression with the reading of the command line input without using an if statement?

Answer 1

Try this code:

$result = ($port_number =~ m/^[0-9]{1,5}$/);

$result will be set to 1 if the $port_number matches your criteria, and will be set to 0 otherwise.