while (<FH>) is "shorthand" for: while (defined( $_=<FH>)), and the defined can sometimes be important if your last entry in a file is a 0 without \n afterwards. And normally, I don't want to miss a single zero at the end which could even happen with <> if you pipe in a file.
Good worry, but no need to lose sleep since Perl's behaviour has been adapted to do the right thing in the real world a while ago.
$ perl -MO=Deparse -e'1 while my $line = <>;'
'???' while defined(my $line = <ARGV>);
-e syntax OK
$ perl -v
This is perl, v5.6.1 built for i386-linux
I'm not sure exactly when it changed;
perldoc perldelta for 5.6.1 doesn't mention it and I can't seem to find any mention in older versions of the POD found on
perldoc.com either. Of course even on older Perls, you can use the
my construct by simply adding the
defined yourself..
while(defined(my $line = <>)){
# ...
}
Makeshifts last the longest.
