Add the --colormap option to build adhoc colormaps

Use the given list of comma-separated colors as a colormap (cycle the colors at each match).
Support of 256 colors mode colormaps.

README.md

@@ -28,10 +28,13 @@ rapid_blink, reverse, conceal or random.
 `Random` will color each matching pattern with a random color among the 255
 available in the ANSI table. `random` will do the same in 8 colors mode.
 
+`rainbow` will cycle over a 8 colors rainbow at each matching pattern.
+
 When not specified, a *COLOR* defaults to _red_ and a *STYLE* defaults to _bold_.
 
 `colout` is released under the GNU Public License v3.
 
+
 ## OPTIONS
 
 * `-h`, `--help`:
@@ -43,14 +46,17 @@ When not specified, a *COLOR* defaults to _red_ and a *STYLE* defaults to _bold_
 * `-g`, `--groups`:
   For color maps (like "rainbow"), iterate over matching groups in the pattern instead of over patterns.
 
+* `-c`, `--colormap`:
+  Use the given list of comma-separated colors as a colormap (cycle the colors at each match).
+
 
 ## REGULAR EXPRESSIONS
 
 A regular expression (or _regex_) is a pattern that describes a set of strings
-that matches it. 
+that matches it.
 
 `colout` understands regex as specifed in the _re_ python module. Given that
-`colout` is generally called by the command line, you may have to escape 
+`colout` is generally called by the command line, you may have to escape
 special characters that would be recognize by your shell.
 
 
@@ -87,6 +93,9 @@ special characters that would be recognize by your shell.
   `make 2>&1 | colout :\([0-9]+\):[0-9]* yellow normal | colout error | colout warning magenta | colout pragma green normal | colout /\(\\w+\)*\.\(h\|cpp\) cyan normal`
 
 * Color each word in the head of auth.log with a rainbow color map, starting a new colormap at each new line (the
-  begining of the command is just bash magic to repeat the string "(\w+
+  begining of the command is just bash magic to repeat the string "(\\w+)\\W+":
   `L=$(seq 10) ; P=${L//??/(\\w+)\\W+} ; head /var/log/auth.log | ./colout.py -g "^${P}(.*)$" rainbow`
 
+* Color each line of a file with a different color among a 256 color gradient from cyan to green:
+  `head /var/log/auth.log | ./colout.py -c "^.*$" 39,38,37,36,35,34`
+

colout.py

@@ -26,7 +26,8 @@ colors = {
 }
 
 rainbow = [ "red", "yellow", "green", "cyan", "blue", "magenta" ]
-rainbow_idx = 0
+colormap = rainbow  # default colormap to rainbow
+colormap_idx = 0
 
 # Escaped end markers for given color modes
 endmarks = {8:";", 256:";38;5;"}
@@ -45,7 +46,7 @@ def colorin( text, color = "red", style = "normal" ):
     >>> colout.colorin("Faites chier la vache", 41, "normal")
     '\x1b[0;38;5;41mFaites chier la vache\x1b[0m'
     """
-    global rainbow_idx
+    global colormap_idx
 
     # Special characters.
     start = "\033["
@@ -71,13 +72,29 @@ def colorin( text, color = "red", style = "normal" ):
 
     elif color == "rainbow":
         mode = 8
-        color = rainbow[rainbow_idx]
+        color = colormap[colormap_idx]
         color_code = str( 30 + colors[color] )
 
-        if rainbow_idx < len(rainbow)-1:
+        if colormap_idx < len(colormap)-1:
-            rainbow_idx += 1
+            colormap_idx += 1
         else:
-            rainbow_idx = 0
+            colormap_idx = 0
+
+    elif color == "colormap":
+        color = colormap[colormap_idx]
+        if color in colors:
+            mode = 8
+            color_code = str( 30 + colors[color] )
+        else:
+            mode = 256
+            color_nb = int( color )
+            assert( 0 <= color_nb <= 255 )
+            color_code = str( color_nb )
+
+        if colormap_idx < len(colormap)-1:
+            colormap_idx += 1
+        else:
+            colormap_idx = 0
 
     # 8 colors modes
     elif color in colors:
@@ -107,7 +124,7 @@ def colorout( text, match, prev_end, color = "red", style = "normal", group=0 ):
     return colored_text,end
 
 
-def colorup( text, pattern, color = "red", style = "normal", on_groups=False ):
+def colorup( text, pattern, color = "red", style = "normal", on_groups=False):
     """
     Color up every characters that match the given regexp patterns.
     If groups are specified, only color up them and not the whole pattern.
@@ -130,7 +147,7 @@ def colorup( text, pattern, color = "red", style = "normal", on_groups=False ):
     >>> colorup("Faites Chier la Vache", "([A-Z])(\S+)\s", "blue", "bold,italic")
     '\x1b[1;34mF\x1b[0m\x1b[3;34maites\x1b[0m \x1b[1;34mC\x1b[0m\x1b[3;34mhier\x1b[0m la Vache'
     """
-    global rainbow_idx
+    global colormap_idx
     regex = re.compile(pattern)#, re.IGNORECASE)
 
     # Prepare the colored text.
@@ -160,7 +177,7 @@ def colorup( text, pattern, color = "red", style = "normal", on_groups=False ):
             # If we want to iterate colormaps on groups instead of patterns
             if on_groups:
                 # Reset the counter at the beginning of each match
-                rainbow_idx = 0
+                colormap_idx = 0
 
             # For each group index.
             # Note that match.groups returns a tuple (thus being indexed in [0,n[),
@@ -176,7 +193,7 @@ def colorup( text, pattern, color = "red", style = "normal", on_groups=False ):
     return colored_text
 
 
-def colorgen( items, pattern, color = "red", style = "normal", on_groups=False ):
+def colorgen( items, pattern, color = "red", style = "normal", on_groups=False):
     """
     A generator that colors the items given in an iterable input.
 
@@ -186,7 +203,7 @@ def colorgen( items, pattern, color = "red", style = "normal", on_groups=False )
      '2.7\x1b[0;31m1\x1b[0m828\x1b[0;31m1\x1b[0m82846']
     """
     for item in items:
-        yield colorup( item, pattern, color, style, on_groups )
+        yield colorup( item, pattern, color, style, on_groups)
 
 
 ######################
@@ -239,8 +256,10 @@ def __args_dirty__(argv,usage=""):
                 on_stderr = bool(argv[4])
                 if len(argv) == 6:
                     on_groups = bool(argv[5])
+                    if len(argv) == 7:
+                        as_colormap = bool(argv[6])
 
-    return pattern,color,style,on_stderr,on_groups
+    return pattern,color,style,on_stderr,on_groups,as_colormap
 
 
 def __args_parse__(argv,usage=""):
@@ -268,11 +287,14 @@ def __args_parse__(argv,usage=""):
             help="Output on the stderr instead of stdout")
 
     parser.add_argument("-g", "--groups", action="store_true",
-            help="For color maps (random, rainbows), iterate over matching groups in the pattern instead of over patterns")
+            help="For color maps (random, rainbow), iterate over matching groups in the pattern instead of over patterns")
+
+    parser.add_argument("-c", "--colormap", action="store_true",
+            help="Use the given colors as a colormap (cycle the colors at each match)")
 
     args = parser.parse_args()
 
-    return args.pattern[0], args.color, args.style, args.stderr, args.groups
+    return args.pattern[0], args.color, args.style, args.stderr, args.groups, args.colormap
 
 
 if __name__ == "__main__":
@@ -285,14 +307,18 @@ if __name__ == "__main__":
 
     # if argparse is not installed
     except ImportError:
-        pattern,color,style,on_stderr,on_groups = __args_dirty__(sys.argv,usage)
+        pattern,color,style,on_stderr,on_groups,as_colormap = __args_dirty__(sys.argv,usage)
 
     # if argparse is available
     else:
-        pattern,color,style,on_stderr,on_groups = __args_parse__(sys.argv,usage)
+        pattern,color,style,on_stderr,on_groups,as_colormap = __args_parse__(sys.argv,usage)
 
     # use the generator: output lines as they come
-    for colored in colorgen( sys.stdin, pattern, color, style, on_groups ):
+    if as_colormap == True and color != "rainbow":
+        colormap = color.split(",")  # replace the colormap by the given colors
+        color = "colormap"  # use the keyword to switch to colormap instead of list of colors
+
+    for colored in colorgen( sys.stdin, pattern, color, style, on_groups):
         if on_stderr:
             sys.stderr.write(colored)
             sys.stderr.flush()