Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!bu.edu!bu-pub.bu.edu!jdh
From: jdh@bu-pub.bu.edu (Jason Heirtzler)
Newsgroups: comp.sys.sgi
Subject: read from pty returns EAGAIN
Message-ID: <78104@bu.edu.bu.edu>
Date: 1 Apr 91 16:12:33 GMT
Sender: news@bu.edu.bu.edu
Organization: Boston University Information Technology
Lines: 15

When I read from a pty that I've set up, it's returning EAGAIN if the
process on the slave side hasn't written anything (yet.)

If I understand the man page(s) correctly, it seems to imply that
you can use fcntl to clear O_NDELAY and O_NONBLOCK on the file descriptor,
and the read from the master side will block until data is ready.  This
doesn't seem to be what is happening, however.   I could kludge it, and
retry the read when (errno==EAGAIN) but that's pretty ugly.  Can someone
let me know what the "proper" way to do this is?

Please send responses via email.  Thanks.

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Jason Heirtzler           (617) 353-2780       jdh@bu-pub.bu.edu
Information Technology    Boston University    ..!bu.edu!bu-pub!jdh