structured main routines. implement file reporter

lib/utils/helpers.sh

@@ -0,0 +1,7 @@
+is_number () {
+  [ ! -z "$1" ] && printf '%f' "$1" &>/dev/null
+}
+
+iso_date () {
+  date -u +"%Y-%m-%dT%H:%M:%SZ"
+}

lib/utils/os.sh

@@ -14,11 +14,13 @@ is_linux ()   { [ $OS_TYPE == 'solaris' ]; }
 is_bsd ()     { [ $OS_TYPE == 'bsd']; }
 is_unknown () { [ $OS_TYPE == 'unknown' ]; }
 
-
-make_temp_dir () {
-  if is_osx; then
+# http://unix.stackexchange.com/a/84980/50905
+if is_osx; then
+  make_temp_dir () {
     mktemp -d -t 'sysmetrics'
-  else
+  }
+else
+  make_temp_dir () {
     mktemp -d
-  fi
-}
+  }
+fi