commented awk programs, removed dangling ws

src/awk/recordings.awk

@@ -1,3 +1,39 @@
+# List recordings
+#
+# parameter file_local_recordings: This is an optional parameter with the path
+#                                  to a file with a MusicBrainz recording ID
+#                                  per line.
+# parameter format:                The format of a recording line including the
+#                                  placeholders <<med>> for medium number,
+#                                  <<nr> for for track number within a medium,
+#                                  <<title>> for the title, <<artist>> for the
+#                                  artist string, and <<duration>> for the
+#                                  track duration.
+# parameter format_local:          String to indicate that the track is locally
+#                                  available
+# parameter format_current:        String to indicate that the track is
+#                                  "currently playing"
+# parameter current_id:            MusicBrainz track ID of a track to be marked
+#                                  as "currently playing"
+#
+# The input to this awk program is a sequence of lines containing the following fields:
+# Field 1: The MusicBrainz ID of the release this track belongs to
+# Field 2: MusicBrainz ID of this track
+# Field 3: Medium number of this track within the release
+# Field 4: Track number of this track within the medium
+# Field 5: Duration of this track in miliseconds
+# Field 6: Title of this track
+# Field 7: Artist of this track
+# Field 8: Path to decoratoin file of this release
+#
+# The output is a sequence of tab-delimited lines containing the following fields:
+# Field 1: Sort value (to sort the track within the release)
+# Field 2: The string `format_local` if the track is locally available
+# Field 3: The string `format_current` if the track has MusicBrainz ID `current_id`
+# Field 4: The track line to be displayed according to `format`
+# Field 5: The MusicBrainz ID of the release this track belongs to
+# Field 6: The MusicBrainz ID of this track ":" separated from the path to the
+#          decoration file of this release
 BEGIN {
   OFS="\t"
   local_recordings[0] = 0