feat(func): Write to journald

Function to write log entries to journald. Update writeLog steering function to use this new backend.

cfddns.sh

@@ -136,6 +136,33 @@ translateLogLevelsToJournalD() {
   esac
 }
 
+# $1: message, $2: level, $3: status, [$4: operation], [$5: code]
+writeJournalDLog() {
+  # not enough information to generate a meaningful log message
+  if [ -z "$1" ] || [ $# -lt 3 ]; then
+    return
+  fi
+
+  J_TIMESTAMP="$(getTimeStamp)"
+  J_PID="$$"
+  J_PRIO="$(translateLogLevelsToJournalD "$2")"
+  J_STAT="$(uppercase "$3")"
+
+  logger --journald <<end
+SYSLOG_TIMESTAMP=${J_TIMESTAMP}
+SYSLOG_FACILITY=3
+SYSLOG_IDENTIFIER=${LOG_PROGRAM_NAME}
+SYSLOG_PID=${J_PID}
+PRIORITY=${J_PRIO}
+STATUS=${J_STAT}
+MESSAGE=$1
+OPERATION=${4:-UNSPECIFIED}
+ERRNO=${5:-0}
+end
+
+  return
+}
+
 # $1: message, $2: level, $3: status, [$4: operation], [$5: code]
 writeJsonLog() {
   # not enough information to generate a meaningful log message
@@ -180,7 +207,7 @@ writeLog() {
   PT_LOG_LEVEL="$(standardizeLogLevels "$2")"
   ([ "$logDebug" -eq 0 ] && [ "$PT_LOG_LEVEL" = "DEBUG" ]) && return
 
-  ([ "$logToJournal" -eq 1 ]) && return # TODO: replace this with function when implemented
+  ([ "$logToJournal" -eq 1 ]) && writeJournalDLog "$@"
   ([ "$useJsonLogFmt" -eq 1 ]) && writeJsonLog "$@"
   ([ "$useSyslogLogFmt" -eq 1 ]) && writePlainTextLog "$@"
 }