Messages in this thread | | | Date | Fri, 22 Jun 2001 12:47:50 +0200 (CEST) | From | Thomas Speck <> | Subject | problem with select() - 2.4.5 |
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Hi ! I have a problem with reading from a serial port using select() under 2.4.5. What I am doing is basically the following:
fd_set readfds; struct timeval timeout; int s;
serialfd = open("/dev/ttyS0", O_RDWR );
init_serial(B9600);
timeout.tv_sec = 2; /* ! */ timeout.tv_usec = 0; FD_ZERO(&readfds); FD_SET(serialfd,&readfds);
s=select(serialfd+1, &readfds, NULL, NULL, &timeout); ...
But s is always equal to 0 even when I am sure there are data to read. If I use
s=select(serialfd+1, NULL, &writefds, NULL, &timeout);
(with the corresponding initialisation of writefds) it returns s=1 and I can write to the serial port. I can see that since the lights of the modem are flashing. I noticed that behavior since I tried to send some "ATZ" with the write-function but I never got the "OK" back.
However, the same programme works under 2.2.19.
Any help, please ?
-- Thomas
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