CE add quit command

ce/ce.c

@@ -25,6 +25,8 @@ struct token {
 static int e_pid;
 static int e_pgid;
 
+static bool run = true;
+
 static void putch (char ch) { mail_send (e_pgid, &ch, 1); }
 void putchar_ (char ch) { putch (ch); }
 
@@ -148,14 +150,18 @@ static void cmd_ls (struct list_node_link* tokens) {
   volume_close ();
 }
 
-static void cmd_help (struct list_node_link* tokens) {
-  (void)tokens;
+static void cmd_quit (void) {
+  run = false;
+  printf ("Goodbye!\n");
+}
 
+static void cmd_help (void) {
   printf ("Available commands:\n");
   printf ("echo <word1> <word2> <word3> ...\n");
   printf ("help\n");
   printf ("cat <file path>\n");
   printf ("ls <directory path>\n");
+  printf ("quit\n");
 }
 
 static void exec_tokens (struct list_node_link* tokens) {
@@ -164,11 +170,13 @@ static void exec_tokens (struct list_node_link* tokens) {
   if (strcmp (cmd_token->buffer, "echo") == 0) {
     cmd_echo (tokens->next);
   } else if (strcmp (cmd_token->buffer, "help") == 0) {
-    cmd_help (tokens->next);
+    cmd_help ();
   } else if (strcmp (cmd_token->buffer, "cat") == 0) {
     cmd_cat (tokens->next);
   } else if (strcmp (cmd_token->buffer, "ls") == 0) {
     cmd_ls (tokens->next);
+  } else if (strcmp (cmd_token->buffer, "quit") == 0) {
+    cmd_quit ();
   } else {
     printf ("ERROR: unknown command '%s'\n", cmd_token->buffer);
   }
@@ -193,7 +201,7 @@ void app_main (void) {
   char line_buffer[LINE_BUFFER_MAX + 1];
   memset (line_buffer, 0, sizeof (line_buffer));
 
-  for (;;) {
+  while (run) {
     printf (PROMPT);
 
     char ch = 0;