From b22f6c7852fd3c21fa0ecb08a6cea99c1687a096 Mon Sep 17 00:00:00 2001
From: Lars Brinkhoff <lars@nocrew.org>
Date: Thu, 11 Apr 2019 11:42:33 +0200
Subject: [PATCH] Fix warnings.

Some versions of glibc need _GNU_SOURCE defined to supply declarations
for popen, pclose, fdopen, and usleep.
---
 tek4010.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tek4010.c b/tek4010.c
index 8da294a..c796c45 100755
--- a/tek4010.c
+++ b/tek4010.c
@@ -38,6 +38,8 @@
                                 
 #define PI2 6.283185307
 
+#define _GNU_SOURCE
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>