Add -lsocket to compile on QNX

configure.ac

@@ -54,8 +54,12 @@ case "${host_os}" in
       *mingw32*)
 		os_win32="true"
 	;;
+      *nto-qnx*)
+		os_qnx="true"
+	;;
 esac
 AM_CONDITIONAL(OS_WIN32, test "$os_win32" = "true")
+AM_CONDITIONAL(OS_QNX, test "$os_qnx" = "true")
 
 # Checks for programs.
 AC_PROG_CC

src/Makefile.am

@@ -16,6 +16,10 @@ if OS_WIN32
 libmodbus_la_LIBADD = -lwsock32
 endif
 
+if OS_QNX
+libmodbus_la_LIBADD = -lsocket
+endif
+
 libmodbus_la_LDFLAGS = $(AM_LDFLAGS) -no-undefined -version-info $(LIBMODBUS_LT_VERSION_INFO)
 
 # Header files to install