functions: add shared helpers (log, read_value, ipcmd_for, resolve_gw, etc.)

router/functions

 
+# --- Shared helpers (used by route-update.sh, route-health.sh) ---
+
+log() { echo "$(date '+%H:%M:%S') $*" ; }
+
+# Read first non-comment non-empty line from a config file
+read_value() { grep -v '^#' "$1" 2>/dev/null | grep -m1 . ; }
+
+# Read all non-comment non-empty lines from a config file
+read_values() { grep -v '^#' "$1" 2>/dev/null | grep . ; }
+
+# Determine ip command for routes directory ("ip" or "ip -6")
+ipcmd_for() { case "$1" in *routes6*) echo "ip -6" ;; *) echo "ip" ;; esac ; }
+
+# Check if option is set in group's options file
+has_option() { [ -f "$1/options" ] && grep -q "^$2$" "$1/options" 2>/dev/null ; }
+
+# Get rule priority from table number (table × 10)
+rule_pref() { echo $(( $1 * 10 )) ; }
+
+# Look up routing table number by name in /etc/iproute2/rt_tables
+table_by_name() { awk -v n="$1" '$2 == n { print $1; exit }' /etc/iproute2/rt_tables 2>/dev/null ; }
+
+# Resolve "default" keyword to actual default gateway
+resolve_default_gw() { $1 route show default | awk '/default/ {print $3; exit}' ; }
+
+# Resolve gateway value: "default" → system default, hostname → IP, IP → as-is
+resolve_gw()
+{
+    local val="$1"
+    local ipcmd="${2:-ip}"
+    case "$val" in
+        default) resolve_default_gw "$ipcmd" ;;
+        *[a-zA-Z]*)
+            if [ "$ipcmd" = "ip -6" ] ; then
+                dig +short AAAA "$val" | grep -m1 ':'
+            else
+                dig +short A "$val" | grep -m1 '[0-9]'
+            fi ;;
+        *) echo "$val" ;;
+    esac
+}
+
+# --- DNS resolution ---
+
 get_ipv4_list()
 {
     echo "$1" | grep -q "[a-z]" || return 0