add simple log-facility (replace when syslogd available)

log_helpers.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+# set -x 
+
+log() {
+    local log_file=/var/log/update_controller.log
+    if [ -f "$log_file" ]; then
+        touch $log_file
+    fi
+    if [ $(wc -l < $log_file) > 100000 ]; then
+        # remove first line
+        sed -e 1d -i $log_file
+    fi
+    message="$(date +'%D_%T'): $*"
+    printf "$message\n"
+    printf "$message\n" >> $log_file
+}
+# log "test message1" "test message2"