Perl Unicode Cookbook: Decode Standard Filehandles as UTF-8

Apr 27, 2012 by Tom Christiansen

℞ 15: Declare STD{IN,OUT,ERR} to be UTF-8

Always convert to and from your desired encoding at the edges of your programs. This includes the standard filehandles STDIN, STDOUT, and STDERR.

As documented in perlrun, the PERL_UNICODE environment variable or the -C command-line flag allow you to tell Perl to encode and decode from and to these filehandles as UTF-8, with the S option:

     $ perl -CS ...
     # or
     $ export PERL_UNICODE=S

Within your program, the open pragma allows you to set the default encoding of these filehandles all at once:

     use open qw(:std :utf8);

Because Perl uses IO layers to implement encoding and decoding, you may also use the binmode operator on filehandles directly:

     binmode(STDIN,  ":encoding(UTF-8)");
     binmode(STDOUT, ":encoding(UTF-8)");
     binmode(STDERR, ":encoding(UTF-8)");

Previous: ℞ 14: Decode @ARGV as Local Encoding

Series Index: The Standard Preamble

Next: ℞ 16: Decode Standard Filehandles as Locale Encoding