xxgdb: all ptys in use

[Alf-Ivar Holm]

Robert Crosbie <swingincelt at gmail.com> writes:

> When running xxgdb as a normal user, I get the following message:
> $ xxgdb
> xxgdb: all ptys in use
>
> I can run it as root or sudo though.  
>
> I'm running Hoary, but not latest.  Is there a setting I can change to fix this?

"strace xxgdb" (on a Hoary updated today) gives a lot of lines like
this (where pty<xx> is the changing part):

    open("/dev/ptyp0", O_RDWR)      = -1 EACCES (Permission denied)

and the file permissions for these are like this:

    crw-rw----  1 root root 2,   0 2005-03-17 20:14 /dev/ptyp0

According to this page (in German):

    http://schueler.eckert-schulen.de/sdb/de/html/ke_devpts-63.html

there is a security reason for that.  The remedy given there did not
work for me (by changing the group to tty and add a +s flag to the
ptys), but if you are the sole user of your box you can run "sudo
chgrp users /dev/pty*" and xxgdb will run.  Note: I don't know what
kind of side effects and security risks this will introduce.

According to pts(4) ("man pts", that is) the /dev/pty* naming scheme
is some kind of pre-Unix98 naming.  Warty seems to use the Unix98 way
only, where they are allocated when needed and called /dev/pts/<n>,
where <n> is the number in use.  Not that xxgdb works in Warty, as it
tried to find /dev/pty* there too:

    open("/dev/ptyp0", O_RDWR)      = -1 ENOENT (No such file or directory)

The lasting fix would be to rewrite xxgdb to use Unix98 ptys I guess
...

Alternatives to xxgdb are ddd and kdbg, both in universe.

	Affi