From c71c35f1cbadab07cc64d80f8b785a32e0bfd9db Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fredrik=20=C3=96hrstr=C3=B6m?= <oehrstroem@gmail.com>
Date: Sun, 9 Aug 2020 17:03:59 +0200
Subject: [PATCH 1/2] Send SIGTERM to pid instead of SIGINT to group.

---
 src/main.cc   | 3 ++-
 src/serial.cc | 6 ++++++
 src/shell.cc  | 2 +-
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/main.cc b/src/main.cc
index ff1be1f..6d194c8 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -97,7 +97,9 @@ provided you with this binary. Read the full license for all details.
         // We want the data visible in the log file asap!
         setbuf(stdout, NULL);
         startUsingCommandline(cmdline.get());
+        exit(0);
     }
+    error("(main) internal error\n");
 }
 
 bool startUsingCommandline(Configuration *config)
@@ -368,7 +370,6 @@ LIST_OF_METERS
     }
 
     manager->waitForStop();
-
     if (config->daemon) {
         notice("(wmbusmeters) shutting down\n");
     }
diff --git a/src/serial.cc b/src/serial.cc
index d97e2e0..a60d194 100644
--- a/src/serial.cc
+++ b/src/serial.cc
@@ -878,6 +878,7 @@ static int openSerialTTY(const char *tty, int baud_rate)
     int rc = 0;
     speed_t speed = 0;
     struct termios tios;
+    //int DTR_flag = TIOCM_DTR;
 
     int fd = open(tty, O_RDWR | O_NOCTTY | O_NONBLOCK);
     if (fd == -1) {
@@ -930,6 +931,11 @@ static int openSerialTTY(const char *tty, int baud_rate)
     rc = tcsetattr(fd, TCSANOW, &tios);
     if (rc < 0) goto err;
 
+    // This code can toggle DTR... maybe necessary
+    // for the pl2303 usb2serial driver/device.
+    //rc = ioctl(fd, TIOCMBIC, &DTR_flag);
+    //if (rc != 0) goto err;
+
     return fd;
 
 err:
diff --git a/src/shell.cc b/src/shell.cc
index acc2ba5..6f46bd0 100644
--- a/src/shell.cc
+++ b/src/shell.cc
@@ -190,7 +190,7 @@ void stopBackgroundShell(int pid)
     // The solution for now is to send sigint to 0, which
     // means send sigint to the whole process group that the
     // sender belongs to.
-    int rc = kill(0, SIGINT);
+    int rc = kill(pid, SIGTERM);
     if (rc < 0) {
         debug("(bgshell) could not sigint pid %d, exited already?\n", pid);
         return;

From a42e8c9a5f7a5540796d1a62cb0e70cff11bb9ba Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fredrik=20=C3=96hrstr=C3=B6m?= <oehrstroem@gmail.com>
Date: Sun, 9 Aug 2020 17:05:55 +0200
Subject: [PATCH 2/2] Updated comment.

---
 src/shell.cc | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/src/shell.cc b/src/shell.cc
index 6f46bd0..e3b31d8 100644
--- a/src/shell.cc
+++ b/src/shell.cc
@@ -179,17 +179,8 @@ void stopBackgroundShell(int pid)
 {
     assert(pid > 0);
 
-    // This will actually stop the entire process group.
-    // But it is ok, for now, since this function is
-    // only called when wmbusmeters is exiting.
-
-    // If we send sigint only to pid, then this will
-    // not always propagate properly to the child processes
-    // of the bgshell, ie rtl_sdr and rtl_wmbus, thus
-    // leaving those hanging in limbo and messing everything up.
-    // The solution for now is to send sigint to 0, which
-    // means send sigint to the whole process group that the
-    // sender belongs to.
+    // Sending SIGTERM to the pid will properly shut down the subshell
+    // and its contents.
     int rc = kill(pid, SIGTERM);
     if (rc < 0) {
         debug("(bgshell) could not sigint pid %d, exited already?\n", pid);