http://qs1969.pair.com?node_id=599720

muba has asked for the wisdom of the Perl Monks concerning the following question:

I'm working on this program that reads two UTF-8 files. One contains a lexicon, the other provides a number of sound change rules. In the end, the program is to apply those rules on the original lexicon and output the soundchanged words.

So far so good. Except that things fail if the BOM (byte order mark) is present in the ruleset file.

I open the file as open my $lexFH, "<:encoding(UTF-8)", $clarg{l} or die "Couldn't open lexicon file $clarg{l}: $!"; so I kinda assume that Perl will handle with this kind of stuff for me.

However, if file contains that BOM, my program does not understand the first line in the file. Ok, so I understand the complete details of why my program has troubles with the line, and in the end it just boils down to the simple fact that it doesn't expect that BOM.

And neither did I. I had hoped that Perl would understand it as part of the utf-8 encoding.

By the way, I read my lines as while (my $line = <$lexFH>) {.

So. The actual question I'm trying to ask is this: how do I make Perl understand the BOM in a way that my program never sees it?