On Wed, 30 Aug 2023, Brook Milligan wrote:
I am trying to communicate with uart4 on a Beaglebone Black, but cannot open /dev/tty01; open(2) just hangs.[...] #ls -l /dev/tty01 crw------- 1 uucp wheel 12, 1 Apr 11 12:20 /dev/tty01 However, when run by root, the following code just hangs, i.e., the open() never returns. #include <fcntl.h> int main () { int fd; char const* filename = "/dev/tty01"; fd = open(filename,O_RDWR); }
If you open a dial-in device without O_NONBLOCK, then open() won't return until the carrier is asserted. Does Ctrl-C (or kill -9) end the program? -RVP
