Add random and rainbow

Use "random" as a color or a style to pick a random one for each pattern.
Use "rainbow" as a color to alternate colors in rainbow gradient.
Fix #1

README.md

@@ -19,11 +19,11 @@ with commas. If you indicate more colors than groups, the last ones will be igno
 If you ask for less colors, the last one will be duplicated across remaining
 groups.
 
-Available colors are: blue, black, yellow, cyan, green, magenta, white, red or 
+Available colors are: blue, black, yellow, cyan, green, magenta, white, red,
-any number between 0 and 255.
+rainbow, random, or any number between 0 and 255.
 
 Available styles are: normal, bold, faint, italic, underline, blink,
-rapid_blink, reverse, conceal.
+rapid_blink, reverse, conceal or random.
 
 When not specified, a *COLOR* defaults to _red_ and a *STYLE* defaults to _bold_.
 
@@ -56,6 +56,9 @@ special characters that would be recognize by your shell.
 * Color in bold violet home directories in _/etc/passwd_:
   `colout /home/[a-z]+ 135 < /etc/passwd`
 
+* Use a different color for each line of the auth log
+  `grep user /var/log/auth.log | colout "^.*$" rainbow`
+
 * Color in yellow user/groups id, in bold green name and in bold red home directories in _/etc/passwd_:
   `colout :x:\([0-9]+:[0-9]+\):\([a-z]+\).*\(/home/[a-z]+\) yellow,green,red normal,bold < /etc/passwd`
 

colout.py

@@ -3,10 +3,10 @@
 
 # Color Up Arbitrary Command Ouput 
 # Licensed under the GPL version 3
-# 2012 (c) nojhan <nojhan@gmail.com>
+# 2012 (c) nojhan <nojhan@nojhan.net>
 
 import re
-
+import random
 
 ###########
 # Library #
@@ -25,6 +25,9 @@ colors = {
     "magenta":5, "cyan":6, "white":7
 }
 
+rainbow = [ "red", "yellow", "green", "cyan", "blue", "magenta" ]
+rainbow_idx = 0
+
 # Escaped end markers for given color modes
 endmarks = {8:";", 256:";38;5;"}
 
@@ -47,11 +50,31 @@ def colorin( text, color = "red", style = "normal" ):
     stop = "\033[0m"
 
     # Convert the style code
+    if style == "random":
+        style = random.choice(list(styles.keys()))
+    else:
         assert( style in styles)
+
     style_code = str(styles[style])
 
+    if color == "random":
+        mode = 8
+        color_code = random.choice(list(colors.values()))
+        color_code = str( 30 + color_code )
+
+    elif color == "rainbow":
+        global rainbow_idx
+        mode = 8
+        color = rainbow[rainbow_idx]
+        color_code = str( 30 + colors[color] )
+
+        if rainbow_idx < len(rainbow)-1:
+            rainbow_idx += 1
+        else:
+            rainbow_idx = 0
+
     # 8 colors modes
-    if color in colors: 
+    elif color in colors:
         mode = 8
         color_code = str( 30 + colors[color] )