MD5 Cracker "Perl"

#!/usr/bin/perl
 $ver = "01";
 $dbgtmr = "1"; #Intervall of showing the current speed + lastpassword in seconds.

 if ($dbgtmr<=0){ die "Set dbgtmr to a value >=1 !\n";};
 use Digest::MD5 qw(md5_hex);
 use Time::HiRes qw(gettimeofday);

 if ($ARGV[0]=~"a") {
 $alpha = "abcdefghijklmnopqrstuvwxyz";}
 if ($ARGV[0]=~"A") {
 $alpha = $alpha. "ABCDEFGHIJKLMNOPQRSTUVWXYZ";}
 if ($ARGV[0]=~"d") {
 $alpha = $alpha."1234567890";}
 if ($ARGV[0]=~"x") {
 $alpha = $alpha. "!\"\$%&/()=?-.:\\*'-_:.;,";}

 if ($alpha eq "" or $ARGV[3] eq "") {usage();};
 if (length($ARGV[3]) != 32) { die "Sorry but it seems that the MD5 is not valid!\n";};

 print "Selected charset for attack: '$alpha\'\n";
 print "Going to Crack '$ARGV[3]'...\n";

 for (my $t=$ARGV[1];$t<=$ARGV[2];$t++){
 crack ($t);
 }

 sub usage{
 print "\n\nMD5 Hash Bruteforce Kit v_$ver\n";
 print "by unix_chro alias backtrack (311733@yahoo.com)\n";
 print "Member in staff leader:elite-members,ubuntu-hackers\n\n";
 print "USAGE\n";
 print "./md5crack <charset> <mincount> <maxcount> <yourMD5>\n";
 print " Charset can be: [aAdx]\n";
 print " a = {'a','b','c',...}\n";
 print " A = {'A','B','C',...}\n";
 print " d = {'1','2','3',...}\n";
 print " x = {'!','\"',' ',...}\n";
 print "EXAMPLE FOR CRACKING A MD5 HASH\n";
 print "./md5crack.pl ad 1 3 900150983cd24fb0d6963f7d28e17f72\n";
 print " This example tries to crack the given MD5 with all lowercase Alphas and all digits.\n";
 print " MD5 Kit only tries combinations with a length from 1 and 3 characters.\n-------\n";
 print "./md5crack.pl aA 3 3 900150983cd24fb0d6963f7d28e17f72\n";
 print " This example tries to crack the given MD5 with all lowercase Alphas and all uppercase Alphas.\n";
 print " MD5 Kit only tries passwords which length is exactly 3 characters.\n-------\n";
 print "./md5crack.pl aAdx 1 10 900150983cd24fb0d6963f7d28e17f72\n";
 print " This example tries to crack the given MD5 with nearly every character.\n";
 print " MD5 Kit only tries combinations with a length from 1 to 10 characters.\n";
 die "Quitting...\n";
 }

 sub crack{
 $CharSet = shift;
 @RawString = ();
 for (my $i =0;$i<$CharSet;$i++){ $RawString[i] = 0;}
 $Start = gettimeofday();
 do{
 for (my $i =0;$i<$CharSet;$i++){
 if ($RawString[$i] > length($alpha)-1){
 if ($i==$CharSet-1){
 print "Bruteforcing done with $CharSet Chars. No Results.\n";
 $cnt=0;
 return false;
 }
 $RawString[$i+1]++;
 $RawString[$i]=0;
 }
 }
 ################################################## #
 $ret = "";
 for (my $i =0;$i<$CharSet;$i++){ $ret = $ret . substr($alpha,$RawString[$i],1);}
 $hash = md5_hex($ret);
 $cnt++;
 $Stop = gettimeofday();
 if ($Stop-$Start>$dbgtmr){
 $cnt = int($cnt/$dbgtmr);
 print "$cnt hashes\\second.\tLast Pass '$ret\'\n";
 $cnt=0;
 $Start = gettimeofday();
 }
 print "$ARGV[3] != $hash ($ret)\n";
 if ($ARGV[3] eq $hash){
 die "\n**** Password Cracked! => $ret\n";
 }
 ################################################## #
 #checkhash($CharSet)."\n";

 $RawString[0]++;
 }while($RawString[$CharSet-1]<length($alpha));
 }

 sub checkhash{
 $CharSet = shift;
 $ret = "";
 for (my $i =0;$i<$CharSet;$i++){ $ret = $ret . substr($alpha,$RawString[$i],1);}
 $hash = md5_hex($ret);
 $cnt++;
 $Stop = gettimeofday();
 if ($Stop-$Start>$dbgtmr){
 $cnt = int($cnt/$dbgtmr);
 print "$cnt hashes\\second.\tLast Pass '$ret\'\n";
 $cnt=0;
 $Start = gettimeofday();
 }

 if ($ARGV[3] eq $hash){
 die "\n**** Password Cracked! => $ret\n";
 }

 }