Perl Unicode Cookbook: The Standard Preamble

Editor’s note: Perl guru Tom Christiansen created and maintains a list of 44 recipes for working with Unicode in Perl 5. This is the first recipe in the series.

℞ 0: Standard preamble

Unless otherwise noted, all examples in this cookbook require this standard preamble to work correctly, with the #! adjusted to work on your system:

 #!/usr/bin/env perl

 use utf8;      # so literals and identifiers can be in UTF-8
 use v5.12;     # or later to get "unicode_strings" feature
 use strict;    # quote strings, declare variables
 use warnings;  # on by default
 use warnings  qw(FATAL utf8);    # fatalize encoding glitches
 use open      qw(:std :utf8);    # undeclared streams in UTF-8
 use charnames qw(:full :short);  # unneeded in v5.16

This does make even Unix programmers binmode your binary streams, or open them with :raw, but that’s the only way to get at them portably anyway.

WARNING: use autodie and use open do not get along with each other.

This combination of features sets Perl to a known state of Unicode compatibility and strictness, so that subsequent operations behave as you expect.

The other recipes in this cookbook are:



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