How can I stop my script instead of progressing - perl

Question

I did a simple script using perl and I was wondering how I can pause the program or return it to the action before? I have this code
print "put your name:";
$s=<>;
and it didn't output anything. I want the program to repeat the same action, i.e. asking the user to enter his name instead of progressing.

Answer 1

my $s = '';
while ($s eq '') {
print "put your name:";
chomp($s = <>);
}
print "The name you entered is $s \n";

Answer 2

No need to set $name to anything before you start - just define it:
my $name;
while ( not length $name ) { #Thx Dave Cross
print "What is your name? ";
$name = <STDIN>;
chomp $name;
}
In Perl, variables defined with my (and that should be 99% of your variables) have a limited scope. If they're defined in a block (something that uses curly braces like this while loop), they'll lose their value once they leave the block. That's why I have to have my $name; before the while.
The while ( not $name ) { will work if $name isn't defined or is a null value, so this will loop until I enter something into $name that's not null.
The chomp removes the NL character that I enter when I press the <ENTER> key. You should always chomp your variables after a read of any sort. Just get use to it.
In this form, the loop is self documenting. I am looping while $name isn't filled in.
You can combine the chomp with the input like this:
my $name;
while ( not $name ) {
print "What is your name? ";
chomp ( $name = <STDIN> );
}
Some people like this because it's a bit shorter, but I don't know if its any clearer. I'm a fan of code clarity because it's easier to maintain.

Answer 3

sub readstr {
while (my $in = <>) {
chomp $in;
return $in if length $in;
}
"";
}
print "put your name:";
my $s = readstr();