tab@music4:~/Pianoforte/Perlmonks 21:54:45 $ cat !$
cat 11156670.pl
#!/usr/bin/perl

use strict;
use warnings;

# use Math::BigNum;

{
    print "Log of .5 is " .  log(0.5) . "\n";
}
tab@music4:~/Pianoforte/Perlmonks 21:54:51 $ ./11156670.pl 
Log of .5 is -0.693147180559945
tab@music4:~/Pianoforte/Perlmonks 21:54:57 $