--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test-v22/user_cmd.c	Thu Mar 07 02:33:49 2024 -0800
@@ -0,0 +1,58 @@
+/*
+ * In this module we implement stdin command handling, supporting
+ * user-initiated CANCEL and BYE.
+ */
+
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+
+static void
+pcm_fill_cmd(arg)
+	char *arg;
+{
+	char *cp;
+	unsigned octet;
+
+	for (cp = arg; isspace(*cp); cp++)
+		;
+	if (!isxdigit(*cp)) {
+inv_syntax:	fprintf(stderr, "error: pcm-fill command invalid syntax\n");
+		return;
+	}
+	octet = strtoul(cp, &cp, 16);
+	if (*cp)
+		goto inv_syntax;
+	if (octet > 0xFF) {
+		fprintf(stderr,
+			"error: pcm-fill octet argument out of range\n");
+		return;
+	}
+	set_pcm_fill_octet(octet);
+}
+
+void
+select_stdin()
+{
+	char buf[256], *cp;
+
+	fgets(buf, sizeof buf, stdin);
+	cp = index(buf, '\n');
+	if (cp) {
+		while (cp > buf && isspace(cp[-1]))
+			cp--;
+		*cp = '\0';
+	}
+	for (cp = buf; isspace(*cp); cp++)
+		;
+	if (!*cp)
+		return;
+	if (!strcmp(cp, "b") || !strcasecmp(cp, "bye"))
+		send_bye_req();
+	else if (!strcmp(cp, "c") || !strcasecmp(cp, "cancel"))
+		send_cancel_req();
+	else
+		fprintf(stderr, "error: non-understood stdin command\n");
+}