Matthew Burgess wrote: > ### RATIONALE FOR REMOVAL ### ptmx - isn't directly accessed by a > user. /etc/fstab dictates pty perms
That's incorrect; this change would break PTYs completely.
In order to create a PTY, the master process opens /dev/ptmx. That's
the pseudo-terminal master file for every slave that gets created. Then
you call grantpt() and unlockpt() on the returned FD, to do some magic.
(It's in the manpage, but I'm too lazy to go look at it right now.)
Then you call ptsname() on the FD, to get the slave device's name, and
finally you can open that slave device.
The devpts filesystem creates the *slaves*, not the master. The
permissions in fstab must therefore be applied to only the slaves.
(And I just tried it, too. I changed the owner and group of /dev/ptmx
to root:root 0660, and tried running various programs that I know needed
PTYs:
$ xterm
xterm: Error 32, errno 2: No such file or directory
Reason: get_pty: not enough ptys
$ /tools/bin/expect -c "spawn ls"
spawn ls
The system has no more ptys. Ask your system administrator to create more.
while executing
"spawn ls"
$
(That last error looks familiar, in fact... ;-) )
> printing devices - need non-LFS software to use it
Not entirely correct either, although this is similar to the sound devices:
If your printer supports PostScript natively, you can cat PS files to
your printer device. In fact, even if it doesn't support PS, you can
send the output of GhostScript to the printer device (this is one more
package, but it's nothing on the order of cups or lprng). (I do this
whenever I need to print anything -- I print it to a file, then run the
file through GS with -sOutputFile=/dev/lp0.)
For that matter, all the device categories that the current config file
says "xxxx devices go in their own directory" (sound, input) will now be
cluttering up /dev, which is (at least IMO) the Wrong Thing. Even if
you can't use them yet, I wouldn't think you'd want 10-15 more devices
sitting in the root of /dev -- which is a nonstandard directory for
them, no less.
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