Fix command-line tty-device|config parsing

Allow user to add options on both sides of the provided config argument.

For example:

 $ tio -b 9600 am64-evm -e

Before, tio only allowed adding arguments after the config argument.

Implemented as simple as possible by introducing two stage option parsing.

src/configfile.c

@@ -275,10 +275,9 @@ static int resolve_config_file(void)
     return -EINVAL;
 }
 
-void config_file_parse(const int argc, char *argv[])
+void config_file_parse(void)
 {
     int ret;
-    int i;
 
     c = malloc(sizeof(struct config_t));
     memset(c, 0, sizeof(struct config_t));
@@ -290,14 +289,8 @@ void config_file_parse(const int argc, char *argv[])
         return;
     }
 
-    for (i = 1; i < argc; i++)
+    // Set user input which may be tty device or sub config
-    {
+    c->user = option.tty_device;
-        if (argv[i][0] != '-')
-        {
-            c->user = argv[i];
-            break;
-        }
-    }
 
     if (!c->user)
     {
@@ -333,6 +326,8 @@ void config_file_parse(const int argc, char *argv[])
         fprintf(stderr, "Error: Unable to parse configuration file (%d)", ret);
         exit(EXIT_FAILURE);
     }
+
+    atexit(&config_exit);
 }
 
 void config_exit(void)
@@ -350,7 +345,7 @@ void config_exit(void)
     free(c);
 }
 
-void config_file_print()
+void config_file_print(void)
 {
     if (c->path != NULL)
     {

src/configfile.h

@@ -38,6 +38,6 @@ struct config_t
 	char *map;
 };
 
-void config_file_print();
+void config_file_print(void);
-void config_file_parse(const int argc, char *argv[]);
+void config_file_parse(void);
 void config_exit(void);

src/main.c

@@ -42,13 +42,15 @@ int main(int argc, char *argv[])
     /* Add error exit handler */
     atexit(&error_exit);
 
-    /* Parse configuration file */
+    /* Parse command-line options (1st pass) */
-    config_file_parse(argc, argv);
-    atexit(&config_exit);
-
-    /* Parse command-line options */
     options_parse(argc, argv);
 
+    /* Parse configuration file */
+    config_file_parse();
+
+    /* Parse command-line options (2nd pass) */
+    options_parse_final(argc, argv);
+
     /* List available serial devices */
     if (option.list_devices)
     {

src/options.c

@@ -351,7 +351,7 @@ void options_parse(int argc, char *argv[])
 
     if (strlen(option.tty_device) == 0)
     {
-        printf("Error: Missing device name\n");
+        printf("Error: Missing device or config name\n");
         exit(EXIT_FAILURE);
     }
 
@@ -365,3 +365,16 @@ void options_parse(int argc, char *argv[])
         exit(EXIT_FAILURE);
     }
 }
+
+void options_parse_final(int argc, char *argv[])
+{
+    /* Preserve tty device which may have been set by configuration file */
+    const char *tty_device = option.tty_device;
+
+    /* Do 2nd pass to override settings set by configuration file */
+    optind = 1; // Reset option index to restart scanning of argv
+    options_parse(argc, argv);
+
+    /* Restore tty device */
+    option.tty_device = tty_device;
+}

src/options.h

@@ -63,3 +63,4 @@ extern struct option_t option;
 
 void options_print();
 void options_parse(int argc, char *argv[]);
+void options_parse_final(int argc, char *argv[]);