A perl addition to detect and re-exec itself if PERL_UNICODE env var is set. The var causes STDIN/STDOUT/STDERR to be read as multibyte utf-8 chars instead of just single byte ascii chars. This is useful when operations such as m// or s/// are looking for hex bytes, such as: $line =~ s/\x{e2}\x{94}[\x{8c}-\x{bf}]/+/g;

gistfile1.txt

if (defined $ENV{'PERL_UNICODE'})
  {
  delete $ENV{'PERL_UNICODE'};
  exec ($0, @ARGV);
  }