isjpn2.pl

#!/usr/local/bin/perl

$re_jp   = '\e\$[\@B]';
$re_asc  = '\e\([BJ]';
$re_kana = '\e\(I';

while(<>){
	next unless /[\e\200-\377]/;
	$code = 'japanese',last if(/$re_jp|$re_asc|$re_kana/o); # JIS
	$code = 'binary'  ,last if(/[\000-\006\177\377]/);
	$bin++                  if(/[\200-\376]/);
}

$code = $code || ($bin ? 'japanese' : 'ascii');
print "$code\n";