altos: Provide for a pre-filter on commands

This allows for external code to see each command line before it is
processed and potentially skip it.

Signed-off-by: Keith Packard <keithp@keithp.com>

2 files changed, 13 insertions, 0 deletions

diff --git a/src/ao.h b/src/ao.h
index 2d2bbf82..77f3259e 100644
--- a/src/ao.h
+++ b/src/ao.h
@@ -403,6 +403,14 @@ ao_cmd_register(__code struct ao_cmds *cmds);
 void
 ao_cmd_init(void);
 
+#if HAS_CMD_FILTER
+/*
+ * Provided by an external module to filter raw command lines
+ */
+uint8_t
+ao_cmd_filter(void);
+#endif
+
 /*
  * ao_dma.c
  */
diff --git a/src/ao_cmd.c b/src/ao_cmd.c
index 6007773c..50d5b96f 100644
--- a/src/ao_cmd.c
+++ b/src/ao_cmd.c
@@ -275,6 +275,11 @@ ao_cmd(void)
 	lex_echo = 1;
 	for (;;) {
 		readline();
+#if HAS_CMD_FILTER
+		if (ao_cmd_filter())
+			continue;
+		cmd_i = 0;
+#endif
 		ao_cmd_lex();
 		ao_cmd_white();
 		c = ao_cmd_lex_c;