RMGir explained the problem. Here's a solution: 

for(qw(1 4 haha)){
   eval { usenumbers($_) } or die($@);
}

# Returns true on success.
# Throws an exception on error.
sub usenumbers {
   my $var = shift;
   $var=~/^\d+$/
      or die('Invalid argument: Expecting digits');
   print "Yes, [$var] has numbers.";
   return 1;
}

[download]

A variation of the above where the function doesn't need to return true: 

for(qw(1 4 haha)){
   eval { usenumbers($_) };
   die($@) if $@;
}

# Throws an exception on error.
sub usenumbers {
   my $var = shift;
   $var=~/^\d+$/
      or die('Invalid argument: Expecting digits');
   print "Yes, [$var] has numbers.";
}

[download]

In reply to Re: How do I return false and set an error in special variable $! by ikegami
in thread How do I return false and set an error in special variable $! by leocharre

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