More options processing in Rust

main.c

@@ -38,7 +38,8 @@ extern int optind;
 
 extern void print_message_from_rust();
 extern void print_usage(const char* version);
-extern void radio_list();
+extern void print_usage(const char* version);
+extern int rust_main(int argc, char** argv);
 
 int trace_flag = 0;
 
@@ -46,7 +47,11 @@ void usage() {
   print_usage((const char*)version);
 }
 
-int main(int argc, char **argv)
+int main(int argc, char **argv) {
+  return rust_main(argc, argv);
+}
+
+int old_c_main(int argc, char **argv)
 {
     int read_flag = 0, write_flag = 0, config_flag = 0, csv_flag = 0;
     int list_flag = 0, verify_flag = 0;
@@ -70,10 +75,12 @@ int main(int argc, char **argv)
     }
     argc -= optind;
     argv += optind;
+    /*
     if (list_flag) {
         radio_list();
         exit(0);
     }
+    */
     if (read_flag + write_flag + config_flag + csv_flag + verify_flag > 1) {
         fprintf(stderr, "Only one of -r, -w, -c, -v or -u options is allowed.\n");
         usage();

src/lib.rs

@@ -1,10 +1,16 @@
 use std::ffi::CStr;
-use libc::c_char;
+use libc::{c_int, c_char};
+use getopts::Options;
+use std::process::exit;
 
 mod radio;
 
 const COPYRIGHT: &'static str = "Copyright (C) 2018 Serge Vakulenko KK6ABQ";
 
+extern {
+  fn old_c_main(argc: c_int, argv: *const *const c_char) -> c_int;
+}
+
 #[no_mangle]
 pub extern "C" fn print_usage(version_ptr: *const c_char) {
   let version: String = unsafe { CStr::from_ptr(version_ptr) }.to_string_lossy().to_string();
@@ -38,13 +44,10 @@ Options:
     -l           List all supported radios.
     -t           Trace USB protocol."#;
   print!("{}", msg);
-  std::process::exit(-1);
+  exit(-1);
 }
 
-#[no_mangle]
-pub extern "C" fn process_options() {
-  use getopts::Options;
-
+fn get_options() -> Options {
   let mut opts = Options::new();
   opts.optflag("t", "", "Trace USB protocol.");
   opts.optflag("r", "", "Read codeplug from the radio to a file 'device.img'.\nSave configuration to a text file 'device.conf'.");
@@ -53,7 +56,30 @@ pub extern "C" fn process_options() {
   opts.optflag("u", "", "Update contacts database from CSV file.");
   opts.optflag("l", "", "List all supported radios.");
   opts.optflag("v", "", "Verify configuration script for the radio.");
+  opts
+}
 
+#[no_mangle]
+pub extern "C" fn rust_main(argc: c_int, argv: *const *const c_char) -> c_int {
+
+  let args = std::env::args().skip(1);
+  let matches = match get_options().parse(args) {
+    Ok(m) => m,
+    Err(fail) => {
+      eprintln!("{}", fail);
+      exit(-1);
+    }
+  };
+
+  let list_flag = matches.opt_present("l");
+  if list_flag {
+    radio::list();
+    exit(0);
+  }
+
+  unsafe {
+    old_c_main(argc, argv)
+  }
 }
 
 #[cfg(test)]

src/radio.rs

@@ -2,8 +2,7 @@ extern {
   fn radio_list_c();
 }
 
-#[no_mangle]
-pub extern "C" fn radio_list() {
+pub fn list() {
   unsafe {
     radio_list_c();
   }