#!/usr/bin/perl

# A sample script for MacPerl, which makes a new text file full of prime 
# numbers. The algorithm is inspired by an AppleScript script found in the 
# book of SHODA Tusyano, "Ouyou HyperCard" (Tokyo, ASCII, 1995).
# Written by Kiwada Kats-hiro, 1997-1998.

require "StandardFile.pl";

#$| = 1;

$fname = &StandardFile'PutFile("Make New File as:","primes");	# Make a new file for output.

open(OUT, ">$fname") || die "Cannot save $fname: $!";
select(OUT);
                                                          
$a = time;
$num = 0;
for (2 .. 1000) {						# Set the area to search.
    $answer = $_;
    @prim = ();
    @set = (1,2,2,4);
    $x = $answer;
    $y = 0;
    $z = 2;

    while (($z)**2 <= $x) {
        $d = $x % $z;
        if ($d == 0) {
            $x = $x / $z;
            push(@prim,$z);
        }
        else {
            $z = $z + $set[$y];
            if ($y == 3) {
                $y -= 1;
            }
            else {
                $y += 1;
            }
        }
        next if $x == 1;
        next if (scalar(@prim)) > 1;
    }
    push(@prim,$x) if ($x >= $z);
    if (scalar(@prim) == 1) {					# 10 nums per line.
        print "$answer, ";
        $num += 1;
        if ($num % 10 == 0) {
            print "\n";
        }
    }
}
$b = time;
$c = $b - $a;
print "  $num numbers found. Time spent: $c sec. \n";

&MacPerl'SetFileInfo("YoED", "TEXT", $fname);			# Set "creator" & "type" of the output file.
close(OUT);