Add --get-duration (Fixes #859)

2 files changed, 12 insertions, 2 deletions

diff --git a/youtube_dl/YoutubeDL.py b/youtube_dl/YoutubeDL.py
index ab68d013c..52bd8e0e3 100644
--- a/youtube_dl/YoutubeDL.py
+++ b/youtube_dl/YoutubeDL.py
@@ -34,6 +34,7 @@ from .utils import (
     encodeFilename,
     ExtractorError,
     format_bytes,
+    formatSeconds,
     get_term_width,
     locked_file,
     make_HTTPS_handler,
@@ -94,6 +95,7 @@ class YoutubeDL(object):
     forcethumbnail:    Force printing thumbnail URL.
     forcedescription:  Force printing description.
     forcefilename:     Force printing final filename.
+    forceduration:     Force printing duration.
     forcejson:         Force printing info_dict as JSON.
     simulate:          Do not download the video files.
     format:            Video format code.
@@ -765,6 +767,8 @@ class YoutubeDL(object):
             self.to_stdout(info_dict['description'])
         if self.params.get('forcefilename', False) and filename is not None:
             self.to_stdout(filename)
+        if self.params.get('forceduration', False) and info_dict.get('duration') is not None:
+            self.to_stdout(formatSeconds(info_dict['duration']))
         if self.params.get('forceformat', False):
             self.to_stdout(info_dict['format'])
         if self.params.get('forcejson', False):
diff --git a/youtube_dl/__init__.py b/youtube_dl/__init__.py
index 437c37541..d5c0a3643 100644
--- a/youtube_dl/__init__.py
+++ b/youtube_dl/__init__.py
@@ -298,6 +298,9 @@ def parseOpts(overrideArguments=None):
     verbosity.add_option('--get-description',
             action='store_true', dest='getdescription',
             help='simulate, quiet but print video description', default=False)
+    verbosity.add_option('--get-duration',
+            action='store_true', dest='getduration',
+            help='simulate, quiet but print video length', default=False)
     verbosity.add_option('--get-filename',
             action='store_true', dest='getfilename',
             help='simulate, quiet but print output filename', default=False)
@@ -617,22 +620,25 @@ def _real_main(argv=None):
                      u' file! Use "{0}.%(ext)s" instead of "{0}" as the output'
                      u' template'.format(outtmpl))
 
+    any_printing = opts.geturl or opts.gettitle or opts.getid or opts.getthumbnail or opts.getdescription or opts.getfilename or opts.getformat or opts.getduration or opts.dumpjson
+
     ydl_opts = {
         'usenetrc': opts.usenetrc,
         'username': opts.username,
         'password': opts.password,
         'videopassword': opts.videopassword,
-        'quiet': (opts.quiet or opts.geturl or opts.gettitle or opts.getid or opts.getthumbnail or opts.getdescription or opts.getfilename or opts.getformat or opts.dumpjson),
+        'quiet': (opts.quiet or any_printing),
         'forceurl': opts.geturl,
         'forcetitle': opts.gettitle,
         'forceid': opts.getid,
         'forcethumbnail': opts.getthumbnail,
         'forcedescription': opts.getdescription,
+        'forceduration': opts.getduration,
         'forcefilename': opts.getfilename,
         'forceformat': opts.getformat,
         'forcejson': opts.dumpjson,
         'simulate': opts.simulate,
-        'skip_download': (opts.skip_download or opts.simulate or opts.geturl or opts.gettitle or opts.getid or opts.getthumbnail or opts.getdescription or opts.getfilename or opts.getformat or opts.dumpjson),
+        'skip_download': (opts.skip_download or opts.simulate or any_printing),
         'format': opts.format,
         'format_limit': opts.format_limit,
         'listformats': opts.listformats,