Repeat last command by hitting Enter

main.c

@@ -18,6 +18,7 @@ main(int argc, char *argv[])
     size_t max_command_length = 1023;
     int command_length = 0;
     char *command = malloc(max_command_length + 1);
+    char *last_command = malloc(max_command_length + 1);
     
     process.base_address = 0x555555554000UL; // get_executable_base_address(file, proc.pid);
     process.main_address = get_address_of_subroutine(process.elf, "main");
@@ -35,6 +36,11 @@ main(int argc, char *argv[])
     construct_line_number_table(process.elf, process.sp_table, process.source_file_names, 0, 0);
     
     while ((command_length = getline(&command, &max_command_length, stdin))) {
+        if (command_length == 1) {
+            memset(command, 0, max_command_length);
+            memcpy(command, last_command, command_length);
+        }
+        
         if (0 == strncmp(command, "exit\n", command_length) || 0 == strncmp(command, "q\n", command_length)) {
             break;
         } else if (0 == strncmp(command, "regs\n", command_length)) {
@@ -55,6 +61,9 @@ main(int argc, char *argv[])
             printf("Unknown command: %*s", command_length, command);
         }
         
+        memset(last_command, 0, max_command_length);
+        memcpy(last_command, command, command_length);
+        
         printf("> ");
     }