#!perl -w

use warnings;
use strict;

use Inline C => Config =>
    USING => 'ParseRegExp',
    BUILD_NOISY => 1;

use Inline C => <<'EOC';

void foo(char * x, int y) {
  PerlIO_write(PerlIO_stderr(), x, y); 
}

EOC

my $str = "hello world\n";

foo($str, length($str));
foo($str, 8);

__END__
Outputs:
hello world
hello wo