PATCH: 3.1.5-pws-6: ttys revisited

[Peter Stephenson <pws@ibmth.df.unipi.it>]

ioctl for non-exclusive tty use:

"Bart Schaefer" wrote:
> (For PWS et al.) Even if it should always be done, I think it'd be a good
> idea to move this code down the point where an attempt to open /dev/tty
> might be made anyway, so that it needn't be opened and closed more than
> once.

That seems to be sensible.  This patch will do the whole thing pretty
cheaply: only the `if (SHTTY == -1 && errno == EBUSY)' is usually
executed.

--- Src/init.c.nxcl2	Mon Feb  1 15:28:02 1999
+++ Src/init.c	Wed Feb  3 12:01:41 1999
@@ -301,22 +301,19 @@
 
     /* Make sure the tty is opened read/write. */
     if (isatty(0)) {
+	zsfree(ttystrname);
+	if ((ttystrname = ztrdup(ttyname(0)))) {
+	    SHTTY = movefd(open(ttystrname, O_RDWR | O_NOCTTY));
 #ifdef TIOCNXCL
-	/*
-	 * See if the terminal claims to be busy.  If so, and fd 0
-	 * is a terminal, try and set non-exclusive use for that.
-	 * This is something to do with Solaris over-cleverness.
-	 */
-	int tmpfd;
-	if ((tmpfd = open("/dev/tty", O_RDWR | O_NOCTTY)) < 0) {
-	    if (errno == EBUSY)
+	    /*
+	     * See if the terminal claims to be busy.  If so, and fd 0
+	     * is a terminal, try and set non-exclusive use for that.
+	     * This is something to do with Solaris over-cleverness.
+	     */
+	    if (SHTTY == -1 && errno == EBUSY)
 		ioctl(0, TIOCNXCL, 0);
-	} else
-	    close(tmpfd);
 #endif
-	zsfree(ttystrname);
-	if ((ttystrname = ztrdup(ttyname(0))))
-	    SHTTY = movefd(open(ttystrname, O_RDWR | O_NOCTTY));
+	}
 	/*
 	 * xterm, rxvt and probably all terminal emulators except
 	 * dtterm on Solaris 2.6 & 7 have a bug. Applications are

-- 
Peter Stephenson <pws@ibmth.df.unipi.it>       Tel: +39 050 844536
WWW:  http://www.ifh.de/~pws/
Dipartimento di Fisica, Via Buonarroti 2, 56127 Pisa, Italy