Hello Fedora-list, I am having an issue implementing timeouts on read() to a RS232 serial line /dev/ttySx on both Fedora 5 and Fedora 7. No sorry I don't yet have Fedora 8 or 9. Iv'e tried on multiple machines and multiple types of serial card. Same result. As I am a Fedora novice/dunce, though an OS/2 ace, I'm hoping someone will take pity on my erroneous life choice to a dead end. As far as I can so far tell, the titled flag bits of 'termios' and 'open' do not function as advertised (non-canonical mode). In my instant case I issue a write of 8 bytes which correctly Tx out on the interface. Then I issue a read to get a reply (49 bytes from remote system). I experience the following behaviour:- open without O_NDELAY:- VMIN=50, VTIME=50 read completes OK with correct 49 bytes of data. open without O_NDELAY:- VMIN=49, VTIME=50 OK same as above open without O_NDELAY:- VMIN=48, VTIME=50 hangs infinitely even though sniffer shows correct 49 byte response. open without O_NDELAY:- VMIN=0, VTIME=50 hangs infinitely even though sniffer shows correct 49 byte response. open with O_NDELAY gets immediate negative completion of read, with perror displaying "Resource temporarily unavailable" open with O_NONBLOCK gets same as O_NDELAY (probably same bit POSIX vs non-POSIX). It looks like a bug to me unless there are some undocumented prerequisite/un-requisite flag bits I've omitted setting or clearing. Does anybody have an example of a non-canonical read from a RS232 serial port which actually *will* timeout under Fedora 7? Thanks, JeffP ... the OS/2 waif. -- fedora-list mailing list fedora-list@xxxxxxxxxx To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list
