Re: lynx-dev peculiar behavior

[Klaus Weide]

On Sat, 10 Jul 1999, T.E.Dickey wrote:

> > Larry, to eliminate one factor first: does this also happen outside 
> > of screen?  If you have other ways to log into that system (xterm, 
> > telnet, ...), is it independant of that? 
> it's independent of screen.  (I'm logged in using minicom to Solaris 2.6 and
> can see this effect).

Does adding a sigaction call for SIGCHLD with SA_NOCLDSTOP (anywhere
before the system() in question) change the behavior?

According to my linux man page, SA_NOCLDSTOP is POSIX.
Supposedly,
              SA_NOCLDSTOP
                     If signum is SIGCHLD, do not receive notifi-
                     cation when child processes stop (i.e., when
                     child  processes  receive  one  of  SIGSTOP,
                     SIGTSTP, SIGTTIN or SIGTTOU).

(But there are also these mysterious words:
       POSIX (B.3.3.1.3) disallows setting the action for SIGCHLD
       to SIG_IGN.  The BSD and SYSV behaviours  differ,  causing
       BSD  software  that sets the action for SIGCHLD to SIG_IGN
       to fail on Linux.
)

My guess is that system() is implemented in a way that the waitfoo()
call gets woken up when the child state changes to STOPPED and
system() then returns prematurely.

   Klaus