gipert · April 29, 2019 15:12 · Apr 29, 2019
diff --git a/daemon.sh b/daemon.sh
@@ -0,0 +1,77 @@
+#!/bin/bash
+#
+# simple bash daemon skeleton
+#
+# Author: Luigi Pertoldi - [email protected]
+# Created: Mon 29 Apr 2019
+
+usage() {
+    echo >&2 "USAGE: `basename $0` [OPTIONS]"
+    echo >&2 ""
+    echo >&2 "  OPTIONS:"
+    echo >&2 "    -v, --verbose         : enable verbose mode"
+    echo >&2 "    -r, --refresh <n-sec> : set refresh interval (default 10)"
+    echo >&2 "    -d, --daemon          : start indaemon mode"
+    echo >&2 "    -k, --kill            : kill all running qwatch daemons"
+    echo >&2 "    -h, --help            : display this help message and exit"
+    exit 1;
+}
+
+refresh=10
+daemon=false
+
+options='r:u:vhkd'
+longoptions='refresh:,daemon,kill,help'
+parsed=$(getopt --name `basename $0` --options $options --longoptions $longoptions -- "$@")
+[ $? -eq 0 ] || exit 1
+eval set -- "$parsed"
+while true; do
+    case "$1" in
+        -v)
+            set -xv
+            shift
+            ;;
+        -r | --refresh)
+            refresh=$2
+            shift 2
+            ;;
+        -k | --kill)
+            killall -s TERM qwatch
+            exit
+            ;;
+        -d | --daemon)
+            daemon=true
+            shift
+            ;;
+        --)
+            shift
+            break
+            ;;
+        -h | --help | *)
+          usage
+          ;;
+    esac
+done
+
+# main loop
+routine() {
+    trap "echo 'INFO: quitting gracefully'; exit 1" TERM INT QUIT
+    trap "echo \"daemon [pid $$] exited unexpectedly.\"; exit 1" SEGV BUS ILL HUP ABRT
+
+    while true; do
+        sleep $refresh
+
+        # do your stuff
+        # ...
+    done
+}
+
+# to daemonize or not to daemonize?
+if [ $daemon = true ]; then
+    routine &
+    disown
+    echo "INFO: process started in background with pid $$"
+else
+    echo "INFO: starting routine, use Ctrl+C to kill."
+    routine
+fi