GNU AWK solution for week 103, part 2

2 files changed, 76 insertions, 0 deletions

diff --git a/challenge-103/abigail/README.md b/challenge-103/abigail/README.md
index d35895761f..4059ddea7e 100644
--- a/challenge-103/abigail/README.md
+++ b/challenge-103/abigail/README.md
@@ -123,6 +123,7 @@ Output:
 ~~~~
 
 ### Solutions
+* [GNU AWK](awk/ch-2.awk)
 * [Lua](lua/ch-2.lua)
 * [Perl](perl/ch-2.pl)
 * [Python](python/ch-2.py)
diff --git a/challenge-103/abigail/awk/ch-2.gawk b/challenge-103/abigail/awk/ch-2.gawk
new file mode 100644
index 0000000000..301730b203
--- /dev/null
+++ b/challenge-103/abigail/awk/ch-2.gawk
@@ -0,0 +1,75 @@
+#!/usr/bin/awk
+
+#
+# See ../README.md
+#
+
+#
+# Run as: gawk -f ch-2.gawk < input-file
+#
+
+#
+# We're reading a start time, the current time, and a file name
+# from STDIN, separated by white space. The file contains the
+# tracks played.
+#
+{
+    start_time   = $1
+    current_time = $2
+    file_name    = $3
+
+    time_diff = (current_time - start_time) * 1000
+
+    nr_of_tracks = 1
+    total_time = 0
+    while ((getline track < file_name > 0)) {
+        #
+        # AWK doesn't have the ability to limit the number of
+        # fields a string is split into, so we use index() and
+        # substring() instead of split() to get the info.
+        #
+        j        = index  (track, ",")
+        run_time = substr (track, 1, j - 1)
+        title    = substr (track, j + 1)
+        tracks [nr_of_tracks, 0] = run_time
+        tracks [nr_of_tracks, 1] = title
+        nr_of_tracks ++
+
+        total_time += run_time
+    }
+
+    #
+    # We're not interested in playing full loops.
+    #
+    time_diff %= total_time
+
+    #
+    # Find the current track playing. If time_diff is less than the
+    # play time of the track, this is the track currently playing. If
+    # so, print the track name (with quotes, as given in the example --
+    # although they don't belong there, as they're from the CSV encoding;
+    # for that reason, we won't deescape anything else either). Otherwise
+    # (track length is shorter than time_diff), we subtrack the length
+    # of the track from time_diff, and continue checking the next track.
+    #
+    for (i = 1; i <= nr_of_tracks; i ++) {
+        if (time_diff - tracks [i, 0] < 0) {
+            time_diff = int  (time_diff / 1000)
+            hours     = int  (time_diff / 3600)
+            minutes   = int ((time_diff % 3600) / 60)
+            seconds   =       time_diff         % 60
+            print tracks [i, 1]
+            if (hours > 0) {
+                printf ("%02d:%02d:%02d\n", hours, minutes, seconds)
+            }
+            else {
+                printf (     "%02d:%02d\n",        minutes, seconds)
+            }
+
+            break
+        }
+        else {
+            time_diff -= tracks [i, 0]
+        }
+    }
+}