shell: Added noprompt command

Added noprompt command to shell. It will disable printing
the prompt.
For the native port, when feeding commands from a file or
pipe the prompt reprinting after each command (without echoing)
just confuses the user.

Signed-off-by: Alberto Escolar Piedras <[email protected]>

Author: aescolar

doc/subsystems/shell.rst

@@ -53,6 +53,14 @@ Select module commands
 ``select``
  Clears selected module. Restores prompt as well.
 
+Other commands
+==============
+
+``noprompt``
+ This command will disable the shell prompt. The shell will still be fully
+ functional, but the prompt will not be printed each time the shell expects a
+ new command.
+
 Shell configuration
 *******************
 There are two levels of configuration: Infrastructure level and Module level.

subsys/shell/shell.c

@@ -51,6 +51,7 @@ extern struct shell_cmd __shell_cmd_end[];
 static const char *prompt;
 static char default_module_prompt[PROMPT_MAX_LEN];
 static struct shell_module *default_module;
+static bool no_promt;
 
 #define STACKSIZE CONFIG_CONSOLE_SHELL_STACKSIZE
 static K_THREAD_STACK_DEFINE(stack, STACKSIZE);
@@ -338,6 +339,16 @@ static int cmd_exit(int argc, char *argv[])
 	return 0;
 }
 
+static int cmd_noprompt(int argc, char *argv[])
+{
+	no_promt = true;
+	return 0;
+}
+
+#define SHELL_CMD_NOPROMPT "noprompt"
+SHELL_REGISTER_COMMAND(SHELL_CMD_NOPROMPT, cmd_noprompt,
+		       "Disable shell prompt");
+
 static const struct shell_cmd *get_internal(const char *command)
 {
 	static const struct shell_cmd internal_commands[] = {
@@ -350,7 +361,6 @@ static const struct shell_cmd *get_internal(const char *command)
 	return get_cmd(internal_commands, command);
 }
 
-
 int shell_exec(char *line)
 {
 	char *argv[ARGC_MAX + 1], **argv_start = argv;
@@ -424,11 +434,13 @@ static void shell(void *p1, void *p2, void *p3)
 	while (1) {
 		struct console_input *cmd;
 
-		printk("%s", get_prompt());
+		if (!no_promt) {
+			printk("%s", get_prompt());
 #if defined(CONFIG_NATIVE_POSIX_CONSOLE)
-		/* The native printk driver is line buffered */
-		posix_flush_stdout();
+			/* The native printk driver is line buffered */
+			posix_flush_stdout();
 #endif
+		}
 
 		cmd = k_fifo_get(&cmds_queue, K_FOREVER);