lastchange: add a flag to only print the svn revision number

This allows me to change one of the callers to not parse the
"REVISION=1234" output, which will allow me to change that output
in a future change.

BUG=41264

Review URL: http://codereview.chromium.org/6265021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@72170 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 10 insertions, 6 deletions

diff --git a/build/util/lastchange.py b/build/util/lastchange.py
index ff518fc..1846bab 100755
--- a/build/util/lastchange.py
+++ b/build/util/lastchange.py
@@ -71,11 +71,13 @@ def main(argv=None):
   if argv is None:
     argv = sys.argv
 
-  parser = optparse.OptionParser(usage="lastchange.py [-h] [[-o] FILE]")
+  parser = optparse.OptionParser(usage="lastchange.py [options]")
   parser.add_option("-d", "--default-lastchange", metavar="FILE",
                     help="default last change input FILE")
   parser.add_option("-o", "--output", metavar="FILE",
                     help="write last change to FILE")
+  parser.add_option("--revision-only", action='store_true',
+                    help="just print the SVN revision number")
   opts, args = parser.parse_args(argv[1:])
 
   out_file = opts.output
@@ -90,12 +92,14 @@ def main(argv=None):
 
   change = FetchChange(opts.default_lastchange)
 
-  contents = "LASTCHANGE=%s\n" % change
-
-  if out_file:
-    WriteIfChanged(out_file, contents)
+  if opts.revision_only:
+    print change
   else:
-    sys.stdout.write(contents)
+    contents = "LASTCHANGE=%s\n" % change
+    if out_file:
+      WriteIfChanged(out_file, contents)
+    else:
+      sys.stdout.write(contents)
 
   return 0