update dns2tcp.c

1 files changed, 13 insertions, 2 deletions

diff --git a/dns2tcp.c b/dns2tcp.c
index c1f08f7..7267f69 100644
--- a/dns2tcp.c
+++ b/dns2tcp.c
@@ -3,7 +3,18 @@
 #include <uv.h>
 #undef _GNU_SOURCE
 
-int main(void) {
-    LOGINF("[main] hello, world!");
+static void print_command_help(void) {
+    printf("usage: dns2tcp <-L LISTEN_ADDR> <-R REMOTE_ADDR> [-vVh]\n"
+           " -L <ip#port>           udp listen address, it is required\n"
+           " -R <ip#port>           tcp server address, it is required\n"
+           " -v                     print verbose log, default: <disabled>\n"
+           " -V                     print version number of dns2tcp and exit\n"
+           " -h                     print help information of dns2tcp and exit\n"
+           "bug report: https://github.com/zfl9/dns2tcp. email: zfl9.com@gmail.com\n"
+    );
+}
+
+int main() {
+    print_command_help();
     return 0;
 }