perl function warn

The warn function in Perl is used to generate a warning message, which is printed on STDERR. It behaves like die function, but it does not exit the program. Instead, it allows the program to continue execution even after printing the warning message.

Here's an example:

#!/usr/bin/perl

use strict;
use warnings;

my $num = 10;

if ($num > 5) {
    warn "The number is greater than 5";
}

print "Program continues...\n";

In the above example, the warn function is used to print a warning message if the value of $num is greater than 5. The program then continues to execute and prints "Program continues..." on the screen. The warning message is printed on STDERR, which is usually displayed on the screen along with the regular output.