[PATCH v2] checkkconfigsymbols.py: add --no-color option, don't print color to non-TTY

[Andrew Donnellan <andrew.donnellan@au1.ibm.com>]

Only print the ANSI colour escape codes if stdout is a TTY. Useful if
redirecting output to a file or piping to another script.

Also add a new option, --no-color, if the user wants to disable colour
output for whatever reason.

Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>

---

V1->V2:
	- automatically detect non-TTYs and disable colour output.
	  Suggested by Josh Triplett
---
 scripts/checkkconfigsymbols.py | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/scripts/checkkconfigsymbols.py b/scripts/checkkconfigsymbols.py
index df643f6..b140fc9 100755
--- a/scripts/checkkconfigsymbols.py
+++ b/scripts/checkkconfigsymbols.py
@@ -82,6 +82,11 @@ def parse_options():
                       default=False,
                       help="Reset current Git tree even when it's dirty.")
 
+    parser.add_option('', '--no-color', dest='color', action='store_false',
+                      default=True,
+                      help="Don't print colored output. Default when not "
+                           "outputting to a terminal.")
+
     (opts, _) = parser.parse_args()
 
     if opts.commit and opts.diff:
@@ -116,6 +121,9 @@ def main():
     """Main function of this module."""
     opts = parse_options()
 
+    global color
+    color = opts.color and sys.stdout.isatty()
+
     if opts.sim and not opts.commit and not opts.diff:
         sims = find_sims(opts.sim, opts.ignore)
         if sims:
@@ -202,14 +210,14 @@ def yel(string):
     """
     Color %string yellow.
     """
-    return "\033[33m%s\033[0m" % string
+    return "\033[33m%s\033[0m" % string if color else string
 
 
 def red(string):
     """
     Color %string red.
     """
-    return "\033[31m%s\033[0m" % string
+    return "\033[31m%s\033[0m" % string if color else string
 
 
 def execute(cmd):
-- 
Andrew Donnellan              OzLabs, ADL Canberra
andrew.donnellan@au1.ibm.com  IBM Australia Limited