#!/usr/bin/perl
use strict;

my $dir = shift;
if (!$dir or !chdir($dir)) {
    print "Usage: magicsort DIRECTORY\n",
"Will invoke your system's file(1) utility to categorize all the files found\n",
"by magicrescue.\n";
    exit 1;
}

opendir DH, "." or die "opening $dir: $!\n";
while (defined(my $file = readdir DH)) {
    next unless -f $file;

    open FILE, "-|", "file", $file or die "Executing file: $!\n";
    my $idstring = <FILE>;
    close FILE;

    chomp $idstring;
    $idstring =~ s{[/\x00-\x1F]}{_}g;

    if (length($idstring) - 3 < length($file)) {
	print STDERR "Invalid idstring: $idstring";
	next;
    }
    my $dir = substr($idstring, length($file) + 2);
    mkdir $dir;
    rename $file, "$dir/$file" or warn "Cannot move $file: $!\n";
}