Functions to control your serial port's RTS and DTR on Linux

If you need a way to set the Request-To-Send (RTS) and Data-Terminal-Ready (DTR) signals on a serial port there is a great code snippet on the LinuxQuestions forum by Heiko Noordhof.

It provides four straightforward and easy-to-use functions:

int openserial(char *devicename);
void closeserial(void); 
int setDTR(unsigned short level); 
int setRTS(unsigned short level);