feat: add completion script for zsh

misc/igmpgen_completion.zsh

@@ -0,0 +1,40 @@
+#compdef igmpgen
+
+# Function to handle autocompletion for igmpgen
+_igmpgen() {
+    local -a options
+    local -a igmp_types
+
+    # Options for igmpgen
+    options=(
+        '-i[Specify the network interface (e.g., eth0)]'
+        '-t[Specify the IGMP packet type and version (e.g., 1.query)]'
+        '-g[Specify the IGMP group (e.g., 224.0.0.1)]'
+        '-s[Specify the source IP and port (e.g., 192.168.1.1:1234)]'
+        '-d[Specify the destination IP and port (e.g., 224.0.0.2:5678)]'
+        '-n[Specify delay between packets in seconds]'
+    )
+
+    # Available IGMP packet types
+    igmp_types=(
+        '1.query'
+        '1.report'
+        '1.dvmrp'
+        '2.query'
+        '2.report'
+        '2.leave'
+        '3.report'
+    )
+
+    _arguments -s $options && return
+
+    case $words[1] in
+        -t)
+            _describe -t igmp-types 'IGMP packet type' igmp_types
+            return
+            ;;
+    esac
+}
+
+_igmpgen
+