From 3bdad1b302a3ca1d22b0eaeaca1f8957bec1ffe8 Mon Sep 17 00:00:00 2001
From: Michal Bursa <bursa@astro.cas.cz>
Date: Sun, 19 Jan 2020 22:47:05 +0100
Subject: [PATCH] SerialDeviceTTY::working() now uses fstat() to see if device
 is working

---
 src/serial.cc | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/serial.cc b/src/serial.cc
index 3d6e3ce..de9890e 100644
--- a/src/serial.cc
+++ b/src/serial.cc
@@ -29,7 +29,7 @@
 #include <sys/select.h>
 #include <sys/errno.h>
 #include <sys/types.h>
-#include <sys/statvfs.h>
+#include <sys/stat.h>
 #include <stdio.h>
 #include <termios.h>
 #include <unistd.h>
@@ -304,9 +304,11 @@ bool SerialDeviceTTY::send(vector<uchar> &data)
 
 bool SerialDeviceTTY::working()
 {
+    if (fd_ == -1) return false;
+
     // test if the device is working by checking if the virtual file has been deleted using stat
-    struct statvfs sb;
-    int working = (statvfs(device_.c_str(), &sb) == 0);
+    struct stat sb;
+    int working = (fstat(fd_, &sb) == 0);
 
     if (!working) {
         debug("(serial) device %s is gone\n", device_.c_str());