Re: unfinished command executed when TTY is closed

[Jiri Kukacka]

----- chet.ramey@case.edu wrote:

> On 12/18/14, 11:22 AM, Jiri Kukacka wrote:
> 
> > I checked what's going on using truss, and here's what is says (just
> the interesting part):
> > 1197:   read(0, " r", 1)                                = 1
> > 1197:   lwp_sigmask(SIG_SETMASK, 0x00000002, 0x00000000, 0x00000000,
> 0x00000000) = 0xFFBFFEFF [0xFFFFFFFF]
> > 1197:   write(2, " r", 1)                               = 1
> > 1197:   lwp_sigmask(SIG_SETMASK, 0x00000000, 0x00000000, 0x00000000,
> 0x00000000) = 0xFFBFFEFF [0xFFFFFFFF]
> > 1197:   read(0, " e", 1)                                = 1
> > 1197:   lwp_sigmask(SIG_SETMASK, 0x00000002, 0x00000000, 0x00000000,
> 0x00000000) = 0xFFBFFEFF [0xFFFFFFFF]
> > 1197:   write(2, " e", 1)                               = 1
> > 1197:   lwp_sigmask(SIG_SETMASK, 0x00000000, 0x00000000, 0x00000000,
> 0x00000000) = 0xFFBFFEFF [0xFFFFFFFF]
> > 1197:   read(0, 0xFFFF80D532B7FE8C, 1)  (sleeping...)
> > 1197:   read(0, 0xFFFF80D532B7FE8C, 1)                  = 0
> > 1197:   write(2, "\n", 1)                               Err#5 EIO
> 
> OK, this is the problem part.  This looks like a bug in Solaris. 
> There's
> no indication that the kernel sent SIGHUP before changing the behavior
> of
> read and write upon disconnect.
> 
> Can you see whether or not the first bash in the chain gets a SIGHUP
> here?
> (Though I can't see why or how sending a SIGHUP to any process other
> than
> the tty's current foreground process group is useful.)

Well, I can see that SIGHUP got to first bash just a few lines later (and that 
varies with every test, first this, then the other), and then it was passed 
through the chain to current foreground process.
I can have a look at tty in Solaris, but since other shells don't have this 
problem, I think that it would be great to have bash aware of such things as 
well.

> 
> -- 
> ``The lyf so short, the craft so long to lerne.'' - Chaucer
>                ``Ars longa, vita brevis'' - Hippocrates
> Chet Ramey, ITS, CWRU    chet@case.edu   
> http://cnswww.cns.cwru.edu/~chet/