perlmodulecarp

Why should I use Carp instead of warn in Perl?

People keep giving me examples with carp instead of warn. Why? What makes carp better than warn?

Solution

  • carp gives you more info as to where the message comes from (context)

    #!/usr/bin/perl

use Carp;

foo();
bar();
baz();

sub foo {
  warn "foo";
}

sub bar {
  carp "bar";
}

sub baz {
  foo();
  bar(); 
}

    produces

    foo at ./foo.pl line 9.
bar at ./foo.pl line 13
        main::bar() called at ./foo.pl line 6
foo at ./foo.pl line 10.
bar at ./foo.pl line 14
        main::bar() called at ./foo.pl line 19
        main::baz() called at ./foo.pl line 7

    kinda silly for this small program but comes in handy when you want to know who called the method that's carp'ing.