use new num_open_kprobes() function

tools/funccount

@@ -81,9 +81,14 @@ if debug:
 	print(bpf_text)
 b = BPF(text=bpf_text)
 b.attach_kprobe(event_re=pattern, fn_name="trace_count")
+matched = b.num_open_kprobes()
+if matched == 0:
+	print("0 functions matched by \"%s\". Exiting." % args.pattern)
+	exit()
 
 # header
-print("Tracing... Ctrl-C to end.")
+print("Tracing %d functions for \"%s\"... Hit Ctrl-C to end." %
+    (matched, args.pattern))
 
 # output
 exiting = 0 if args.interval else 1

tools/funclatency

@@ -121,9 +121,14 @@ def signal_ignore(signal, frame):
 b = BPF(text=bpf_text)
 b.attach_kprobe(event_re=pattern, fn_name="trace_func_entry")
 b.attach_kretprobe(event_re=pattern, fn_name="trace_func_return")
+matched = b.num_open_kprobes()
+if matched == 0:
+	print("0 functions matched by \"%s\". Exiting." % args.pattern)
+	exit()
 
 # header
-print("Tracing %s... Hit Ctrl-C to end." % args.pattern)
+print("Tracing %d functions for \"%s\"... Hit Ctrl-C to end." %
+    (matched / 2, args.pattern))
 
 # output
 exiting = 0 if args.interval else 1