diff --git a/.gitignore b/.gitignore
index f8743a5..655afe5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 /vde_vmnet
+*.o
diff --git a/Makefile b/Makefile
index 5c3eae8..d90c5cd 100644
--- a/Makefile
+++ b/Makefile
@@ -2,12 +2,20 @@ PREFIX ?= /usr/local
 
 CFLAGS ?= -O3
 
-LDFLAGS ?= -lvdeplug -framework vmnet
+VERSION ?= $(shell git describe --match 'v[0-9]*' --dirty='.m' --always --tags)
+CFLAGS += -DVERSION=\"$(VERSION)\"
+
+LDFLAGS += -lvdeplug -framework vmnet
 
 all: vde_vmnet
 
-vde_vmnet: *.c
-	$(CC) $(CFLAGS) -o $@ $(LDFLAGS) $<
+OBJS = $(patsubst %.c, %.o, $(wildcard *.c))
+
+%.o: %.c *.h
+	$(CC) $(CFLAGS) -c $< -o $@
+
+vde_vmnet: $(OBJS)
+	$(CC) $(CFLAGS) -o $@ $(LDFLAGS) $(OBJS)
 
 install.bin: vde_vmnet
 	install vde_vmnet "$(DESTDIR)/$(PREFIX)/bin/vde_vmnet"
@@ -39,4 +47,4 @@ uninstall: uninstall.launchd.plist uninstall.bin
 
 .PHONY: clean
 clean:
-	rm -f vde_vmnet
+	rm -f vde_vmnet *.o
diff --git a/cli.c b/cli.c
new file mode 100644
index 0000000..30781c3
--- /dev/null
+++ b/cli.c
@@ -0,0 +1,86 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <getopt.h>
+
+#include "cli.h"
+
+#ifndef VERSION
+#define VERSION "UNKNOWN"
+#endif
+
+static void print_usage(const char *argv0) {
+  printf("Usage: %s [OPTION]... VDESWITCH\n", argv0);
+  printf("vmnet.framework support for rootless QEMU.\n");
+  printf("vde_vmnet does not require QEMU to run as the root user, but "
+         "vde_vmnet itself has to run as the root, in most cases.\n");
+  printf("\n");
+  printf("--vde-group=GROUP        VDE group name (default: \"staff\")\n");
+  printf("-h, --help               display this help and exit\n");
+  printf("-v, --version            display version information and exit\n");
+  printf("\n");
+  printf("version: " VERSION "\n");
+}
+
+static void print_version() { puts(VERSION); }
+
+#define CLI_OPTIONS_ID_VDE_GROUP -42
+struct cli_options *cli_options_parse(int argc, char *argv[]) {
+  struct cli_options *res = malloc(sizeof(*res));
+  if (res == NULL) {
+    goto error;
+  }
+  memset(res, 0, sizeof(*res));
+  res->vde_group = strdup("staff"); /* use strdup to make it freeable */
+
+  const struct option longopts[] = {
+      {"vde-group", required_argument, NULL, CLI_OPTIONS_ID_VDE_GROUP},
+      {"help", no_argument, NULL, 'h'},
+      {"version", no_argument, NULL, 'v'},
+      {0, 0, 0, 0},
+  };
+  int opt = 0;
+  while ((opt = getopt_long(argc, argv, "hv", longopts, NULL)) != -1) {
+    switch (opt) {
+    case CLI_OPTIONS_ID_VDE_GROUP:
+      res->vde_group = strdup(optarg);
+      break;
+    case 'h':
+      print_usage(argv[0]);
+      cli_options_destroy(res);
+      exit(EXIT_SUCCESS);
+      return NULL;
+      break;
+    case 'v':
+      print_version();
+      cli_options_destroy(res);
+      exit(EXIT_SUCCESS);
+      return NULL;
+      break;
+    default:
+      goto error;
+      break;
+    }
+  }
+  if (argc - optind != 1) {
+    goto error;
+  }
+  res->vde_switch = strdup(argv[optind]);
+  return res;
+error:
+  print_usage(argv[0]);
+  cli_options_destroy(res);
+  exit(EXIT_FAILURE);
+  return NULL;
+}
+
+void cli_options_destroy(struct cli_options *x) {
+  if (x == NULL)
+    return;
+  if (x->vde_group != NULL)
+    free(x->vde_group);
+  if (x->vde_switch != NULL)
+    free(x->vde_switch);
+  free(x);
+}
diff --git a/cli.h b/cli.h
new file mode 100644
index 0000000..858f2b3
--- /dev/null
+++ b/cli.h
@@ -0,0 +1,12 @@
+#ifndef VDE_VMNET_CLI_H
+#define VDE_VMNET_CLI_H
+
+struct cli_options {
+  char *vde_group;  // --vde-group
+  char *vde_switch; // arg
+};
+
+struct cli_options *cli_options_parse(int argc, char *argv[]);
+void cli_options_destroy(struct cli_options *);
+
+#endif /* VDE_VMNET_CLI_H */
diff --git a/main.c b/main.c
index dbffefa..af301fb 100644
--- a/main.c
+++ b/main.c
@@ -1,9 +1,14 @@
-#include <libvdeplug.h>
+#include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/uio.h>
+
 #include <vmnet/vmnet.h>
 
+#include <libvdeplug.h>
+
+#include "cli.h"
+
 static bool debug = false;
 
 #define DEBUGF(fmt, ...)                                                       \
@@ -218,26 +223,22 @@ int main(int argc, char *argv[]) {
   debug = getenv("DEBUG") != NULL;
   int rc = 1;
   VDECONN *vdeconn = NULL;
-  char *vdeswitch = NULL; // don't free
   __block interface_ref iface = NULL;
   void *buf = NULL;
-  if (argc != 2) {
-    fprintf(stderr, "Usage: %s VDESWITCH\n", argv[0]);
-    return 1;
-  }
+  struct cli_options *cliopt = cli_options_parse(argc, argv);
+  assert(cliopt != NULL);
   if (geteuid() != 0) {
     fprintf(stderr, "WARNING: Running without root. This is very unlikely to "
                     "work. See README.md .\n");
   }
-  vdeswitch = argv[1];
+  DEBUGF("Opening VDE \"%s\" (for UNIX group \"%s\")", cliopt->vde_switch,
+         cliopt->vde_group);
   struct vde_open_args vdeargs = {
-      .port = 0,        // VDE switch port number, not TCP port number
-      .group = "staff", // TODO: this shouldn't be hard-coded ?
+      .port = 0, // VDE switch port number, not TCP port number
+      .group = cliopt->vde_group,
       .mode = 0770,
   };
-  DEBUGF("Opening VDE \"%s\" (for UNIX group \"%s\")", vdeswitch,
-         vdeargs.group);
-  vdeconn = vde_open(vdeswitch, "vde_vmnet", &vdeargs);
+  vdeconn = vde_open(cliopt->vde_switch, "vde_vmnet", &vdeargs);
   if (vdeconn == NULL) {
     perror("vde_open");
     goto done;
@@ -296,5 +297,6 @@ int main(int argc, char *argv[]) {
   if (buf != NULL) {
     free(buf);
   }
+  cli_options_destroy(cliopt);
   return rc;
 }