diff --git a/tools/rules-test-cases.yaml b/tools/rules-test-cases.yaml
new file mode 100644
index 000000000..1dec1ed2c
--- /dev/null
+++ b/tools/rules-test-cases.yaml
@@ -0,0 +1,796 @@
+---
+::
+  input: |
+    AbCd
+    abcd
+    ABCD
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    AbCd
+    abcd
+    ABCD
+
+l:
+  input: |
+    AbCd
+    abcd
+    ABCD
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    abcd
+    abcd
+    abcd
+
+u:
+  input: |
+    AbCd
+    abcd
+    ABCD
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    ABCD
+    ABCD
+    ABCD
+
+c:
+  input: |
+    AbCd
+    abcd
+    ABCD
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    Abcd
+    Abcd
+    Abcd
+
+C:
+  input: |
+    AbCd
+    abcd
+    ABCD
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    aBCD
+    aBCD
+    aBCD
+
+t:
+  input: |
+    AbCd
+    abcd
+    ABCD
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    aBcD
+    ABCD
+    abcd
+
+T5:
+  input: |
+    AbCde
+    abcdef
+    ABCDEFg
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    AbCde
+    abcdeF
+    ABCDEfg
+
+r:
+  input: |
+    AbCd
+    abcd
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    dCbA
+    dcba
+
+d:
+  input: |
+    3abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    3abc3abc
+
+ddd:
+  input: |
+    3ab
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    3ab3ab3ab3ab3ab3ab3ab3ab
+
+p0:
+  input: |
+    3abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    3abc
+
+p3:
+  input: |
+    3abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    3abc3abc3abc3abc
+
+f:
+  input: |
+    3abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    3abccba3
+
+'{':
+  input: |
+    3abc
+    a
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    abc3
+    a
+
+'}':
+  input: |
+    3abc
+    a
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    c3ab
+    a
+
+$1$2:
+  input: |
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    abc12
+
+^1^2:
+  input: |
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    21abc
+
+'[':
+  input: |
+    a
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+
+    bc
+
+']':
+  input: |
+    a
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+
+    ab
+
+D3:
+  input: |
+    abc
+    abcd
+    abcde
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    abc
+    abc
+    abce
+
+x14:
+  input: |
+    a
+    abc
+    abcde
+    abcdef
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    abc
+    bcde
+    bcde
+
+O22:
+  input: |
+    a
+    ab
+    abc
+    abcd
+    abcde
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    ab
+    abc
+    ab
+    abe
+
+O04:
+  input: |
+    a
+    abc
+    abcd
+    abcde
+    abcdef
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    abc
+
+    e
+    ef
+
+i3!:
+  input: |
+    a
+    abc
+    abcd
+    abcde
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    abc!
+    abc!d
+    abc!de
+
+o3!:
+  input: |
+    a
+    abc
+    abcd
+    abcde
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    abc
+    abc!
+    abc!e
+
+'''4':
+  input: |
+    a
+    abc
+    abcd
+    abcde
+    abcdef
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+    123456790abcdefghijklmnopqrstuvwxyz
+    123456790abcdefghijklmnopqrstuvwxyzA
+    123456790abcdefghijklmnopqrstuvwxyzAB
+    123456790abcdefghijklmnopqrstuvwxyzABC
+    123456790abcdefghijklmnopqrstuvwxyzABCDEF
+
+  expected_output: |
+    a
+    abc
+    abcd
+    abcd
+    abcd
+
+sab:
+  input: |
+    123b
+    a123ba
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    123b
+    b123bb
+
+saa:
+  input: |
+    123b
+    a123ba
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    123b
+    a123ba
+
+'@a':
+  input: |
+    123b
+    aaa
+    a123ba
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    123b
+
+    123b
+
+z0:
+  input: |
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    abc
+
+z3:
+  input: |
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    aaaabc
+
+Z0:
+  input: |
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    abc
+
+Z3:
+  input: |
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    abcccc
+
+q:
+  input: |
+    a
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    aa
+    aabbcc
+
+qqq:
+  input: |
+    a
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    aaaaaaaa
+    aaaaaaaabbbbbbbbcccccccc
+
+uMlX134:
+  mode: 1
+  input: |
+    a
+    abc
+    abcd
+    abcdef
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    abcdBCD
+    abcdBCDef
+
+uMl4:
+  mode: 1
+  input: |
+    a
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    aA
+    abcABC
+
+uMl6:
+  mode: 1
+  input: |
+    a
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    Aa
+    ABCabc
+
+<0:
+  mode: 1
+  input: |
+    a
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+
+<1:
+  mode: 1
+  input: |
+    a
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+
+'>0':
+  mode: 1
+  input: |
+    a
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    abc
+
+'>2':
+  mode: 1
+  input: |
+    a
+    ab
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    ab
+    abc
+
+'!a':
+  mode: 1
+  input: |
+    1
+    ab
+    abc
+    bcde
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    1
+    bcde
+
+/a:
+  mode: 1
+  input: |
+    1
+    ab
+    abc
+    bcde
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    ab
+    abc
+
+(a:
+  mode: 1
+  input: |
+    1
+    ab
+    bac
+    abc
+    bcde
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    ab
+    abc
+
+)c:
+  mode: 1
+  input: |
+    1
+    ab
+    bac
+    abc
+    bcde
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    bac
+    abc
+
+=2c:
+  mode: 1
+  input: |
+    1
+    ab
+    bac
+    abc
+    bcde
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    bac
+    abc
+
+'%2a':
+  mode: 1
+  input: |
+    a
+    aa
+    aaa
+    aaaa
+    bcde
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    aaa
+    aaaa
+
+Q:
+  mode: 1
+  input: |
+    a
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    abc
+
+rMrQ:
+  mode: 1
+  input: |
+    ab
+    abcba
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    ab
+
+k:
+  input: |
+    a
+    ab
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    ba
+    bac
+
+K:
+  input: |
+    a
+    ab
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    ba
+    acb
+
+'*24':
+  input: |
+    a
+    ab
+    abc
+    abcd
+    abcde
+    abcdef
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    ab
+    abc
+    abcd
+    abedc
+    abedcf
+
+L2:
+  input: |
+    a
+    ab
+    ab!
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    ab
+    abB
+
+R2:
+  input: |
+    a
+    ab
+    abB
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    ab
+    ab!
+
++2:
+  input: |
+    a
+    ab
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    ab
+    abd
+
+-2:
+  input: |
+    a
+    ab
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    ab
+    abb
+
+.2:
+  input: |
+    a
+    ab
+    abc
+    abcd
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    ab
+    abc
+    abdd
+
+',2':
+  input: |
+    a
+    ab
+    abc
+    abcd
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    ab
+    abb
+    abbd
+
+y2:
+  input: |
+    a
+    ab
+    abc
+    123456790abcdefghijklmnopqrst
+    123456790abcdefghijklmnopqrstu
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    abab
+    ababc
+    12123456790abcdefghijklmnopqrst
+
+Y2:
+  input: |
+    a
+    ab
+    abc
+    123456790abcdefghijklmnopqrst
+    123456790abcdefghijklmnopqrstu
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    a
+    abab
+    abcbc
+    123456790abcdefghijklmnopqrstst
+
+E:
+  input: |
+    a bc
+    ab c
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    A Bc
+    Ab C
+    Abc
+
+e-:
+  input: |
+    a-bc
+    ab-c
+    abc
+    123456790abcdefghijklmnopqrstuvw
+    123456790abcdefghijklmnopqrstuvwx
+
+  expected_output: |
+    A-Bc
+    Ab-C
+    Abc
diff --git a/tools/test_rules.pl b/tools/test_rules.pl
new file mode 100644
index 000000000..7247196c8
--- /dev/null
+++ b/tools/test_rules.pl
@@ -0,0 +1,194 @@
+#!/usr/bin/env perl
+
+##
+## Author......: See docs/credits.txt
+## License.....: MIT
+##
+
+use strict;
+use warnings;
+use Digest::MD5    qw (md5_hex);
+use File::Basename qw (dirname);
+use YAML::XS          "LoadFile";
+use Test::More;
+
+# Use `eq_or_diff` from Test::Differences if it's available for an easier to read comparison
+# between expected and actual output.
+# Fall back to `is` from Test::More if it isn't available.
+
+BEGIN
+{
+  if (!eval q{ use Test::Differences; 1 })
+  {
+    *eq_or_diff = \&is;
+  }
+}
+
+
+my $hashcat     = "./hashcat";
+my $OPTS        = "--stdout --force";
+my $CURRENT_DIR = dirname (__FILE__);
+my $OUT_DIR     = $CURRENT_DIR . "/". "rules-test";
+
+mkdir $OUT_DIR || die $! unless -d $OUT_DIR;
+
+# Make sure to cleanup on forced exit
+$SIG{INT} = \&cleanup_and_exit;
+
+my %cases = load_cases ();
+
+if (scalar @ARGV > 2 || defined $ARGV[0] && $ARGV[0] eq '--help')
+{
+  usage_die ();
+}
+elsif (scalar @ARGV == 1)
+{
+  my $rule = $ARGV[0];
+
+  die ("No test case was found for rule: $rule") unless exists $cases{$rule};
+
+  run_case_all_mods ($rule);
+}
+elsif (scalar @ARGV == 2)
+{
+  my $rule = $ARGV[0];
+  my $mode = $ARGV[1];
+
+  die ("No test case was found for rule: $rule") unless exists $cases{$rule};
+
+  if ($mode == 1)
+  {
+    run_case_mode1 ($rule);
+  }
+  elsif ($mode == 2)
+  {
+    run_case_mode2 ($rule);
+  }
+  else
+  {
+    die ("Invalid mode: $mode. Mode can be either 1 or 2.");
+  }
+}
+else
+{
+  run_case_all_mods ($_) for (sort keys %cases);
+}
+
+cleanup ();
+
+done_testing ();
+
+
+# Mode 1: host mode, using -j
+
+sub run_case_mode1
+{
+  my $rule = shift;
+
+  my $case       = $cases{$rule};
+  my $input_file = input_to_file ($case, $rule);
+
+  my $quoted_rule   = quotemeta ($rule);
+  my $actual_output = qx($hashcat $OPTS -j $quoted_rule $input_file);
+
+  eq_or_diff ($actual_output, $case->{expected_output}, $rule . " - mode 1");
+}
+
+# Mode 2: GPU mode, using -r
+
+sub run_case_mode2
+{
+  my $rule = shift;
+
+  my $case       = $cases{$rule};
+  my $input_file = input_to_file ($case, $rule);
+  my $rule_file  = rule_to_file ($rule);
+
+  my $quoted_rule   = quotemeta ($rule);
+  my $actual_output = qx($hashcat $OPTS -r $rule_file $input_file);
+
+  eq_or_diff ($actual_output, $case->{expected_output}, $rule . " - mode 2");
+}
+
+sub run_case_all_mods
+{
+  my $rule = shift;
+
+  my $case = $cases{$rule};
+
+  if (defined $case->{mode})
+  {
+    run_case_mode1 ($rule) if $case->{mode} == 1;
+    run_case_mode2 ($rule) if $case->{mode} == 2;
+  }
+  else
+  {
+    run_case_mode1 ($rule);
+    run_case_mode2 ($rule);
+  }
+}
+
+sub input_to_file
+{
+  my $case = shift;
+  my $rule = shift;
+
+  my $file_name = $OUT_DIR . "/" . rule_file_name ($rule);
+  open my $fh, ">", $file_name || die $!;
+  print $fh $case->{input};
+  close $fh;
+
+  return $file_name;
+}
+
+sub rule_to_file
+{
+  my $rule = shift;
+
+  my $file_name = $OUT_DIR . "/" . rule_file_name ($rule, "rule");
+  open my $fh, ">", $file_name || die $!;
+  print $fh $rule;
+  close $fh;
+
+  return $file_name;
+}
+
+sub rule_file_name
+{
+  my $rule = shift;
+  my $ext  = shift || "in";
+
+  return sprintf ("rule-%s.%s", md5_hex ($rule), $ext);
+}
+
+sub usage_die
+{
+  die ("usage: $0 [rule] [mode] \n" .
+       "       [mode]: 1 for host mode, 2 for GPU mode \n" .
+       "       If [rule] was not specified, run all test cases \n" .
+       "       If [mode] was not specified, run test for all modes \n" .
+       "\n" .
+       "examples: \n" .
+       "run i3! case on modes 1 & 2  : perl $0 i3! \n" .
+       "run O04 case on mode 1       : perl $0 O04 1 \n" .
+       "run sab case on mode 2       : perl $0 sab 2 \n");
+}
+
+sub load_cases
+{
+  my $file_path = $CURRENT_DIR . "/" . "rules-test-cases.yaml";
+  return %{ LoadFile($file_path) };
+}
+
+sub cleanup
+{
+  unlink <$OUT_DIR/*.in $OUT_DIR/*.rule>;
+  rmdir $OUT_DIR;
+}
+
+sub cleanup_and_exit
+{
+  cleanup ();
+  done_testing ();
+  exit 0;
+}