app/testpmd: show output of commands read from file

Testpmd supports the "--cmdline-file" parameter to read a set of initial
commands from a file. However, the only indication that this has been
done successfully on startup is a single-line message, no output from
the commands is seen.

To improve usability here, we can use cmdline_new rather than
cmdline_file_new and have the output from the various commands sent to
stdout, allowing the user to see better what is happening.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Ferruh Yigit <ferruh.yigit@amd.com>

app/test-pmd/cmdline.c

@@ -6,6 +6,7 @@
 #include <ctype.h>
 #include <stdarg.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
@@ -13677,7 +13678,18 @@ cmdline_read_from_file(const char *filename)
 {
 	struct cmdline *cl;
 
-	cl = cmdline_file_new(main_ctx, "testpmd> ", filename);
+	/* cmdline_file_new does not produce any output which is not ideal here.
+	 * Much better to show output of the commands, so we open filename directly
+	 * and then pass that to cmdline_new with stdout as the output path.
+	 */
+	int fd = open(filename, O_RDONLY);
+	if (fd < 0) {
+		fprintf(stderr, "Failed to open file %s: %s\n",
+			filename, strerror(errno));
+		return;
+	}
+
+	cl = cmdline_new(main_ctx, "testpmd> ", fd, STDOUT_FILENO);
 	if (cl == NULL) {
 		fprintf(stderr,
 			"Failed to create file based cmdline context: %s\n",