--- a/pcm/pcm_tx.c	Sun Jun 23 19:21:00 2024 +0000
+++ b/pcm/pcm_tx.c	Sun Jun 23 19:30:40 2024 +0000
@@ -2,6 +2,7 @@
  * In this module we implement PCM Tx toward the TRAU.
  */
 
+#include <ctype.h>
 #include <stdint.h>
 #include <stdbool.h>
 #include <stdio.h>
@@ -54,3 +55,24 @@
 		memset(buf, pcm_fill_octet, 160);
 	write(ts_fd, buf, 160);
 }
+
+void cmd_pcm_fill(int argc, char **argv)
+{
+	u_long val;
+	char *cp;
+
+	if (argc != 2) {
+		printf("error: pcm-fill command needs 1 argument\n");
+		return;
+	}
+	if (!isxdigit(argv[1][0])) {
+inv_arg:	printf("error: argument is not a valid hex octet\n");
+		return;
+	}
+	val = strtoul(argv[1], &cp, 16);
+	if (*cp)
+		goto inv_arg;
+	if (val > 0xFF)
+		goto inv_arg;
+	pcm_fill_octet = val;
+}