Control-c not work under openssh?

Nils Ellmenreich Nils at InfoSun.FMI.Uni-Passau.De
Wed Jul 5 18:17:58 EST 2000

>>>"JH" == John Horne <J.Horne at> writes:

 JH> I'm using openSSH 2.1.1p2 from my Linux PC to Solaris 7 and 8 systems (using
 JH> 2.1.1p1). No problem, except that if I run a program on the Sun, having used
 JH> slogin to connect to it, and then try and issue a control-c to break into
 JH> the program it seems to be ignored. I can control-z and then kill the


I got the same problem and want to add some details that might help to
track down the problem.

We have a heterogeneous environment of Solaris 2.6 and 8 and Linux, most
using ssh 1.x and some OpenSSH 2.1.1p1. After some testing, we are
certain that the problem is with the OpenSSH daemon. The ctrl-c is
ignored whenever the target host runs this sshd on Solaris 8 (didn't try
2.6; no problem on Linux). The problem exists, if the user has a Bourne
shell or a bash. However, if you invoke (in a broken tty/shell) either
/bin/su or zsh, ctrl-c works again. The ssty -a output in a broken and
not-broken tty are the same.

<rough guess> 
sshd might be doing something wrong when initializing the
pty/tty. A truss/strace comparison of Solaris 8 and Linux shows that the
Linux sshd does some more ioctls on the tty during login. Maybe su and
zsh repair the problem by default but bash and sh don't.  
</rough guess>

Hope that helps someone who know more about this stuff ... ;-)

Cheers, Nils
Nils Ellmenreich - Fakultaet fuer Math./Informatik             - Nils @  -  Univ. Passau   -   Uni-Passau.DE

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