Messages in this thread |  | | Date | Fri, 13 Dec 1996 12:18:37 -0500 (EST) | From | "Richard B. Johnson" <> | Subject | Serial Patch |
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/*
I installed the latest tty patch. The call to open a non-existant terminal device no longer crashes. However, it now returns a valid handle even if the device does not exist. In this example, there are only TWO RS-232C ports on this machine! An attempt to open /dev/cua3 should return with -1 and the error set to something appropriate.
Interesting that it returns -1 with /dev/cua4, however. I checked to see if there was, perhaps, a "motherboard UART" that I didn't know about.
UARTs exist at 0x2f8 and 0x3f8 only on this machine.
*/
#include <stdio.h> #include <unistd.h> #include <errno.h> #include <sys/fcntl.h>
main() { int fd;
fd = open("/dev/cua3", O_RDWR|O_NONBLOCK, 0); fprintf(stdout, "Open() returned %d, (%s)\n", fd, strerror(errno)); return 0; }
Cheers, Dick Johnson -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Richard B. Johnson Project Engineer Analogic Corporation Voice : (508) 977-3000 ext. 3754 Fax : (508) 532-6097 Modem : (508) 977-6870 Ftp : ftp@boneserver.analogic.com Email : rjohnson@analogic.com, johnson@analogic.com Penguin : Linux version 2.1.15 on an i586 machine. Warning : It's hard to remain at the trailing edge of technology. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
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