Color output for derdump (after "pip install colored")

Thanks to Adriaan for the suggestion!
(You may need to use "less -R" for paging to see the colours)

diff --git a/README.MD b/README.MD
index 56e0f98..51411a4 100644 (file)
--- a/README.MD
+++ b/README.MD
@@ -24,3 +24,7 @@ simplicity, they can be true life savers.
     full of errors; the utility will complain loudly, but continue instead
     of failing fatally; this makes it a very useful developer tool.
 
+    Use the option `--colour` to get output with helpful colouring; the
+    most important information will stand out in bold face.  You can pipe
+    it into `less -R` if you need a colour-friendly pager.
+

diff --git a/derdump b/derdump
index 46fd63f..d841ab8 100755 (executable)
--- a/derdump
+++ b/derdump
@@ -1,29 +1,28 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 
 import sys
 
-if len (sys.argv) != 2:
-       print 'Usage:  ' + sys.argv [0] + 'file.der'
-       print 'Output: MEANING: TAG ###CONTLEN @TAGOFS ^NESTING, CLASS, PRIMCONSTR'
-       sys.exit (1)
+import optparse
 
-der = open (sys.argv [1], 'r').read (65537)
-ofs = 0
+opts = optparse.OptionParser ()
+opts.add_option ('-c', '--colour', '--color',
+               action='store_true', default=False, dest='colour',
+               help='Print colourful output (loads Python module "colored", page with "less -R")')
+(options,args) = opts.parse_args ()
 
-def eof ():
-       global ofs, der
-       return ofs >= len (der)
+if len (args) != 1:
+       print 'Usage:  ' + attr ('bold') + sys.argv [0] + '[--colour] file.der' + attr (0)
+       print 'Output: ' + nicemeaning ('MEANING') + ': ' + nicetag ('TAG') + ' ' + nicecontlen ('CONTLEN', 3) + ' ' + nicetagofs ('TAGOFS') + ' ' + nicenesting ('NESTING') + ', ' + niceclass ('CLASS') + ', ' + niceprimconstr ('PRIMCONSTR')
+       sys.exit (1)
 
-def read1 ():
-       global ofs, der
-       if eof ():
-               print 'ATTEMPTED READ BEYOND EOF (RETURNING 0x00)'
-               return 0
-       else:
-               ofs = ofs + 1
-               return ord (der [ofs-1])
+if options.colour:
+       from colored import fg, bg, attr
+else:
+       def attr (_col):
+               return ''
+       fg = attr
+       bg = attr
 
-nesting = []
 
 class2str = {
        0: 'Universal',
@@ -72,6 +71,63 @@ universal2str = {
        31: '*****'
 }
 
+
+def niceerror (s):
+       return bg ('yellow') + fg ('red') + s + attr (0)
+
+def nicemeaning (s):
+       return attr ('bold') + s + attr (0)
+
+def nicetag (ds):
+       if type (ds) == int:
+               ds = 'tag 0x%02x' % ds
+       return fg ('green') + ds + attr (0)
+
+def nicecontlen (ds, depth):
+       if type (ds) == int:
+               ds = str (ds)
+       return fg ('magenta') + '#' * depth + ds + attr (0)
+
+def nicetagofs (ds):
+       if type (ds) == int:
+               ds = str (ds)
+       return fg ('cyan') + '@' + ds + attr (0)
+
+def nicenesting (ad):
+       if type (ad) == type ([]):
+               ad = len (ad)
+       return fg ('light_blue') + '^' + str (ad) + attr (0)
+
+def niceclass (ds):
+       if type (ds) == int:
+               ds = class2str [ds]
+       return attr ('dim') + ds + attr (0)
+
+def niceprimconstr (ds):
+       if type (ds) == bool:
+               ds = int (ds)
+       if type (ds) == int:
+               ds = pc2str [ds]
+       return attr ('dim') + ds + attr (0)
+
+der = open (args [0], 'r').read (65537)
+ofs = 0
+
+def eof ():
+       global ofs, der
+       return ofs >= len (der)
+
+def read1 ():
+       global ofs, der
+       if eof ():
+               print 'ATTEMPTED READ BEYOND EOF (RETURNING 0x00)'
+               return 0
+       else:
+               ofs = ofs + 1
+               return ord (der [ofs-1])
+
+nesting = []
+
 while not eof ():
 
        while nesting != [] and ofs >= nesting [-1]:
@@ -106,18 +162,18 @@ while not eof ():
        else:
                meaning = '[PRIVATE ' + str (tag_num) + ']'
 
-       print '%s%s: tag 0x%02x %s%d @%d ^%d, %s, %s' % (
+       print ('%s%s: %s %s %s %s, %s, %s' % (
                        '  ' * len (nesting),
-                       meaning, tag,
-                       '#' * lenlen, leng,
-                       ofs - lenlen - 1,
-                       len (nesting),
-                       class2str [tag_class],
-                       pc2str [tag_pc] )
+                       nicemeaning (meaning), nicetag (tag),
+                       nicecontlen (leng, lenlen),
+                       nicetagofs (ofs - lenlen - 1),
+                       nicenesting (nesting),
+                       niceclass (tag_class),
+                       niceprimconstr (tag_pc) ) )
 
        if tag_pc == 0 and leng > 0:
                print '  ' * ( len (nesting) + 1 ),
-               cstr = '"'
+               cstr = ''
                ival = None
                ostr = ''
                oval = None
@@ -141,11 +197,12 @@ while not eof ():
                                        ostr = ostr + '.' + str (oval)
                                        oval = 0
                        leng = leng - 1
-               cstr = cstr + '"'
                if tag == 0x06:
-                       cstr = ostr
+                       cstr = attr ('bold') + ostr + attr (0)
                elif tag == 0x02:
-                       cstr = str (ival)
+                       cstr = attr ('bold') + str (ival) + attr (0)
+               else:
+                       cstr = '"' + attr ('bold') + cstr + attr (0) + '"'
                print '==', cstr
 
        if tag_pc != 0:
@@ -154,6 +211,6 @@ while not eof ():
 
 while nesting != []:
        if ofs != nesting [-1]:
-               print 'NESTING NOT ENDED CORRECTLY, OFFSET IS %d INSTEAD OF %d (CONTINUING)' % (ofs, nesting [-1])
+               print niceerror ('NESTING NOT ENDED CORRECTLY, OFFSET IS %d INSTEAD OF %d (CONTINUING)' % (ofs, nesting [-1]))
        nesting.pop ()
 

diff --git a/derdump-screenshot.png b/derdump-screenshot.png
new file mode 100644 (file)
index 0000000..1ba3bc8
Binary files /dev/null and b/derdump-screenshot.png differ