monitor: support long option, also change -a to -m

Makefile

@@ -58,8 +58,8 @@ $(OBJ_DIR)/%.o: src/%.c
 .PHONY: app run gdb clean run-env $(QEMU_SO)
 app: $(BINARY)
 
-override ARGS ?= -l $(BUILD_DIR)/nemu-log.txt
-override ARGS += -d $(QEMU_SO)
+override ARGS ?= --log=$(BUILD_DIR)/nemu-log.txt
+override ARGS += --diff=$(QEMU_SO)
 
 # Command to execute NEMU
 IMG :=

src/monitor/monitor.c

 #include "nemu.h"
 #include "monitor/monitor.h"
 #include <unistd.h>
+#include <getopt.h>
 
 void init_log(const char *log_file);
 void init_isa();
@@ -64,18 +65,26 @@ static inline long load_img() {
 }
 
 static inline void parse_args(int argc, char *argv[]) {
+  const struct option table[] = {
+    {"batch"    , no_argument      , NULL, 'b'},
+    {"log"      , required_argument, NULL, 'l'},
+    {"diff"     , required_argument, NULL, 'd'},
+    {"mainargs" , required_argument, NULL, 'm'},
+    {"port"     , required_argument, NULL, 'p'},
+    {0          , 0                , NULL,  0 },
+  };
   int o;
-  while ( (o = getopt(argc, argv, "-bl:d:a:p:")) != -1) {
+  while ( (o = getopt_long(argc, argv, "-bl:d:m:p:", table, NULL)) != -1) {
     switch (o) {
       case 'b': is_batch_mode = true; break;
-      case 'a': mainargs = optarg; break;
+      case 'm': mainargs = optarg; break;
       case 'p': sscanf(optarg, "%d", &difftest_port); break;
       case 'l': log_file = optarg; break;
       case 'd': diff_so_file = optarg; break;
       case 1:
-                if (img_file != NULL) Log("too much argument '%s', ignored", optarg);
-                else img_file = optarg;
-                break;
+        if (img_file != NULL) Log("too much argument '%s', ignored", optarg);
+        else img_file = optarg;
+        break;
       default:
                 panic("Usage: %s [-b] [-l log_file] [img_file]", argv[0]);
     }