Add automatic retry

Co-authored-by: Kevin Krotzer <[email protected]>
Co-authored-by: Zach Butler <[email protected]>

entry.sh

@@ -1,9 +1,17 @@
 #!/bin/sh
 while true; do
-    DATE="$(date)"
+    RUN_TIME="$(date '+%s')"
     # shellcheck disable=SC2086
     /zap2xml.pl -u "$USERNAME" -p "$PASSWORD" -U -o "/data/$XMLTV_FILENAME" $OPT_ARGS
-    echo "Last run time: $DATE"
-    echo "Will run in $SLEEPTIME seconds"
-    sleep "$SLEEPTIME"
+    printf 'Run time: '
+    date -d "@$RUN_TIME" '+%F %T %Z'
+    MOD_TIME="$(date -r "/data/$XMLTV_FILENAME" '+%s')"
+    if test "$MOD_TIME" -gt "$RUN_TIME"; then
+        echo "Will run again in $SLEEPTIME seconds."
+        sleep "$SLEEPTIME"
+    else
+        echo 'This run did not complete successfully.'
+        echo 'Pausing for 30 seconds and trying again...'
+        sleep 30
+    fi
 done