Give `varnishadm` a `-p` to disable libreadline and get VCLI compliance.

bin/varnishadm/varnishadm.c

@@ -75,6 +75,7 @@
 
 
 static const double timeout = 5;	// XXX should be settable by arg ?
+static int p_arg = 0;
 
 static void
 cli_write(int sock, const char *s)
@@ -254,7 +255,10 @@ pass_answer(int fd)
 		RL_EXIT(1);
 	}
 
-	printf("%u\n", status);
+	if (p_arg)
+		printf("%-3u %-8zu\n", status, strlen(answer));
+	else
+		printf("%u\n", status);
 	if (answer) {
 		printf("%s\n", answer);
 		free(answer);
@@ -441,7 +445,7 @@ main(int argc, char * const *argv)
 	 * The '+' stops that from happening
 	 * See #1496
 	 */
-	while ((opt = getopt(argc, argv, "+hn:S:T:t:")) != -1) {
+	while ((opt = getopt(argc, argv, "+hn:pS:T:t:")) != -1) {
 		switch (opt) {
 		case 'h':
 			/* Usage help */
@@ -449,6 +453,9 @@ main(int argc, char * const *argv)
 		case 'n':
 			n_arg = optarg;
 			break;
+		case 'p':
+			p_arg = 1;
+			break;
 		case 'S':
 			S_arg = optarg;
 			break;
@@ -485,7 +492,7 @@ main(int argc, char * const *argv)
 		NEEDLESS(exit(0));
 	}
 
-	if (isatty(0))
+	if (isatty(0) && !p_arg)
 		interactive(sock);
 	else
 		pass(sock);

bin/varnishtest/tests/u00012.vtc

@@ -14,15 +14,17 @@ client c1 {
 
 varnish v1 -vsl_catchup
 
-process p1 -log {cat | varnishadm -n ${v1_name}} -start
+process p1 -log {cat | varnishadm -p -n ${v1_name}} -start
 
 process p1 -write "ping\r"
 
+process p1 -expect-text 0 1 "200 19"
+
 process p1 -expect-text 0 1 "PONG"
 
 process p1 -write "vcl.list\r"
 
-process p1 -expect-text 0 0 "auto    warm"
+process p1 -expect-text 0 0 "auto    warm" 
 
 process p1 -write "vcl.show vcl1\r"
 

doc/sphinx/reference/varnishadm.rst

@@ -38,6 +38,11 @@ OPTIONS
 -h
     Print program usage and exit.
 
+-p
+    Force `pass` mode and make the output follow the VCLI protocol.
+    This disables command-history/command-completion and makes it
+    easier for programs to parse the response(s).
+
 -n ident
     Connect to the instance of `varnishd` with this name.