ioctl

[Rob Warnock]

In article <105553 at sgi.sgi.com> I wrote:
+-+-------------
| | an ioctl call is giving me an "Invalid argument error".  The
| | call looks like this:
| | 	if (ioctl(trackerPtr->fileDescriptor, FIONREAD, &charsToRead) < 0)
| +---------------
| ... I just checked, and on Irix 3.3.2, FIONREAD is not supported on
| pipes or plain files. You get errno=25.
+---------------

As a work-around, you might try using select() in polling mode as a (partial)
replacement for icotl(,FIONREAD,). A select() "poll" can be done by providing
a "timeout" argument (a pointer to a "struct timeval"), but making the "timval"
structure pointed to contain all zeros. See the select(2) man page.


-Rob

-----
Rob Warnock, MS-1L/515		rpw3 at sgi.com		rpw3 at pei.com
Silicon Graphics, Inc.		(415)335-1673		Protocol Engines, Inc.
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Mountain View, CA  94039-7311