Add --color and --no-color options.

By default, we auto-detect color mode (if it's a tty, color default on,
else off).  But you can force it either way.

builder.py

@@ -22,7 +22,8 @@ def _try_stat(filename):
 log_reader_pid = None
 
 
-def start_stdin_log_reader(status, details, pretty, debug_locks, debug_pids):
+def start_stdin_log_reader(status, details, pretty, color,
+                           debug_locks, debug_pids):
     if not vars.LOG: return
     global log_reader_pid
     r, w = os.pipe()    # main pipe to redo-log
@@ -47,7 +48,7 @@ def start_stdin_log_reader(status, details, pretty, debug_locks, debug_pids):
         os.dup2(w, 1)
         os.dup2(w, 2)
         os.close(w)
-        check_tty(sys.stderr)
+        check_tty(sys.stderr, vars.COLOR)
     else:
         # child
         try:
@@ -64,8 +65,10 @@ def start_stdin_log_reader(status, details, pretty, debug_locks, debug_pids):
                 ('--pretty' if pretty else '--no-pretty'),
                 ('--debug-locks' if debug_locks else '--no-debug-locks'),
                 ('--debug-pids' if debug_pids else '--no-debug-pids'),
-                '-'
             ]
+            if color != 1:
+                argv.append('--color' if color >= 2 else '--no-color')
+            argv.append('-')
             os.execvp(argv[0], argv)
         except Exception, e:
             sys.stderr.write('redo-log: exec: %s\n' % e)

logs.py

@@ -2,9 +2,10 @@ import os, re, sys, time
 import vars
 
 
-def check_tty(file):
+def check_tty(file, color):
     global RED, GREEN, YELLOW, BOLD, PLAIN
-    if file.isatty() and (os.environ.get('TERM') or 'dumb') != 'dumb':
+    color_ok = file.isatty() and (os.environ.get('TERM') or 'dumb') != 'dumb'
+    if (color and color_ok) or color >= 2:
         # ...use ANSI formatting codes.
         RED    = "\x1b[31m"
         GREEN  = "\x1b[32m"
@@ -98,17 +99,17 @@ class PrettyLog(object):
 
 _log = None
 
-def setup(file, pretty):
+def setup(file, pretty, color):
     global _log
     if pretty or vars.PRETTY:
-        check_tty(file)
+        check_tty(file, color=color)
         _log = PrettyLog(file=file)
     else:
         _log = RawLog(file=file)
 
 
-# FIXME: explicitly initialize in each program
+# FIXME: explicitly initialize in each program, for clarity
-setup(file=sys.stderr, pretty=False)
+setup(file=sys.stderr, pretty=vars.PRETTY, color=vars.COLOR)
 
 
 def write(s):

redo-ifchange.py

@@ -21,7 +21,7 @@ rv = 202
 try:
     if vars_init.is_toplevel:
         builder.start_stdin_log_reader(status=True, details=True,
-            pretty=True, debug_locks=False, debug_pids=False)
+            pretty=True, color=True, debug_locks=False, debug_pids=False)
     if vars.TARGET and not vars.UNLOCKED:
         me = os.path.join(vars.STARTDIR, 
                           os.path.join(vars.PWD, vars.TARGET))

redo-log.py

@@ -10,9 +10,9 @@ r,recursive     show build logs for dependencies too
 u,unchanged     show lines for dependencies not needing to be rebuilt
 f,follow        keep watching for more lines to be appended (like tail -f)
 no-details      only show 'redo' recursion trace, not build output
-no-colorize     don't colorize 'redo' log messages
 no-status       don't display build summary line in --follow
 no-pretty       don't pretty-print logs, show raw @@REDO output instead
+no-color        disable ANSI color; --color to force enable (default: auto)
 debug-locks     print messages about file locking (useful for debugging)
 debug-pids      print process ids in log messages (useful for debugging)
 ack-fd=         (internal use only) print REDO-OK to this fd upon starting
@@ -211,7 +211,7 @@ try:
         sys.exit(1)
     if opt.status < 2 and not os.isatty(2):
         opt.status = False
-    logs.setup(file=sys.stdout, pretty=opt.pretty)
+    logs.setup(file=sys.stdout, pretty=opt.pretty, color=opt.color)
     if opt.debug_locks:
         vars.DEBUG_LOCKS = 1
     if opt.debug_pids:

redo.py

@@ -16,6 +16,7 @@ no-details only show 'redo' recursion trace (to see more later, use redo-log)
 no-status  don't display build summary line at the bottom of the screen
 no-log     don't capture error output, just let it flow straight to stderr
 no-pretty  don't pretty-print logs, show raw @@REDO output instead
+no-color   disable ANSI color; --color to force enable (default: auto)
 debug-locks  print messages about file locking (useful for debugging)
 debug-pids   print process ids as part of log messages (useful for debugging)
 version    print the current version and exit
@@ -51,6 +52,8 @@ if opt.no_log:
     os.environ['REDO_LOG'] = '0'
     if opt.no_pretty:
         os.environ['REDO_PRETTY'] = '0'
+    if opt.no_color:
+        os.environ['REDO_COLOR'] = '0'
 
 import vars_init
 vars_init.init(targets)
@@ -61,7 +64,7 @@ from logs import warn, err
 try:
     if vars_init.is_toplevel:
         builder.start_stdin_log_reader(status=opt.status, details=opt.details,
-            pretty=opt.pretty,
+            pretty=opt.pretty, color=opt.color,
             debug_locks=opt.debug_locks, debug_pids=opt.debug_pids)
     for t in targets:
         if os.path.exists(t):

vars.py

@@ -17,6 +17,7 @@ VERBOSE = os.environ.get('REDO_VERBOSE', '') and 1 or 0
 XTRACE = os.environ.get('REDO_XTRACE', '') and 1 or 0
 KEEP_GOING = os.environ.get('REDO_KEEP_GOING', '') and 1 or 0
 LOG = atoi(os.environ.get('REDO_LOG', '1'))  # defaults on
+COLOR = atoi(os.environ.get('REDO_COLOR', '1'))  # defaults on
 # subprocesses mustn't pretty-print if a parent is running redo-log
 PRETTY = (not LOG) and atoi(os.environ.get('REDO_PRETTY', '1'))
 SHUFFLE = os.environ.get('REDO_SHUFFLE', '') and 1 or 0