* better subshell patch
@ 1995-11-08 9:22 Peter William Stephenson
0 siblings, 0 replies; only message in thread
From: Peter William Stephenson @ 1995-11-08 9:22 UTC (permalink / raw)
To: Zsh hackers list
At Richard's suggestion, here is an improved version of the subshell
patch. It adds an extra flag to entersubsh() indicating if the
subshell is a fake... i.e. we are still in the parent shell but are
preparing to exec an external programme. In that case, the subsh
variable is not set and there will be a real `exit' call after a final
shell function in the parent shell (only).
As I noted in the comments, a `fake' subshell is not the same as a
`fake' exec: even a `real' exec means that we are not really in a
subshell so that entersubsh() gets the fake flag. In the case where
we were having problems yesterday, an internal shell command running
as the last part of a subshell, the subsh flag doesn't get set in the
subshell itself for this reason (and indeed no exec of any kind takes
place; execcmd() doesn't actually test whether the `fake exec' is
actually going to happen, i.e. if it is executing an external command,
which in this case it isn't --- if it had been the problem wouldn't
have arisen); however it has already been set when the command
substitution subshell was originally forked and that is what is being
relied on for the test for _exit. (Alles klar??)
I've also deleted what appear to be a couple of bogus `subsh = 1'
statements just before calls to entersubsh() in hunks 8 and 9. I can
see no reference to subsh between these statements and where it gets
set anyway in entersubsh().
*** Src/exec.c.subsh Tue Nov 7 04:43:04 1995
--- Src/exec.c Wed Nov 8 10:05:22 1995
***************
*** 734,740 ****
}
else {
close(synch[0]);
! entersubsh(Z_ASYNC, 0);
setpgrp(0L, mypgrp = jobtab[list_pipe_job].gleader);
close(synch[1]);
kill(getpid(), SIGSTOP);
--- 734,740 ----
}
else {
close(synch[0]);
! entersubsh(Z_ASYNC, 0, 0);
setpgrp(0L, mypgrp = jobtab[list_pipe_job].gleader);
close(synch[1]);
kill(getpid(), SIGSTOP);
***************
*** 816,822 ****
} else {
close(pipes[0]);
close(synch[0]);
! entersubsh(how, 1);
close(synch[1]);
execcmd(pline->left, input, pipes[1], how, 0);
_exit(lastval);
--- 816,822 ----
} else {
close(pipes[0]);
close(synch[0]);
! entersubsh(how, 1, 0);
close(synch[1]);
execcmd(pline->left, input, pipes[1], how, 0);
_exit(lastval);
***************
*** 1315,1321 ****
/* pid == 0 */
close(synch[0]);
! entersubsh(how, 1);
close(synch[1]);
forked = 1;
if (sigtrapped[SIGINT] == 2)
--- 1315,1321 ----
/* pid == 0 */
close(synch[0]);
! entersubsh(how, 1, 0);
close(synch[1]);
forked = 1;
if (sigtrapped[SIGINT] == 2)
***************
*** 1322,1329 ****
holdintr();
} else if ((cmd->flags & (CFLAG_EXEC|CFLAG_FAKE_EXEC)) && !nullexec) {
! /* this is an `exec' (real or fake) that contains a command */
! entersubsh(how, 1);
} else {
/* Job is running in current shell. */
jobtab[thisjob].stat |= STAT_CURSH;
--- 1322,1332 ----
holdintr();
} else if ((cmd->flags & (CFLAG_EXEC|CFLAG_FAKE_EXEC)) && !nullexec) {
! /* this is an `exec' (real or fake) that contains a command: *
! * note that any form of exec means that the subshell is fake *
! * (but we may be in a subshell already). *
! */
! entersubsh(how, 1, 1);
} else {
/* Job is running in current shell. */
jobtab[thisjob].stat |= STAT_CURSH;
***************
*** 1514,1520 ****
/* only save the history file on a real exec */
if ((cmd->flags & CFLAG_EXEC) && unset(NORCS) && interact)
savehistfile(getsparam("HISTFILE"), 1, isset(APPENDHISTORY) ? 3 : 0);
! exit(lastval);
}
if (!forked && !assign)
--- 1517,1526 ----
/* only save the history file on a real exec */
if ((cmd->flags & CFLAG_EXEC) && unset(NORCS) && interact)
savehistfile(getsparam("HISTFILE"), 1, isset(APPENDHISTORY) ? 3 : 0);
! if (subsh)
! _exit(lastval);
! else
! exit(lastval);
}
if (!forked && !assign)
***************
*** 1634,1640 ****
/**/
void
! entersubsh(int how, int cl)
{
if (sigtrapped[SIGEXIT])
unsettrap(SIGEXIT);
--- 1640,1646 ----
/**/
void
! entersubsh(int how, int cl, int fake)
{
if (sigtrapped[SIGEXIT])
unsettrap(SIGEXIT);
***************
*** 1675,1681 ****
} else
setpgrp(0L, jobtab[thisjob].gleader);
}
! subsh = 1;
if (SHTTY != -1) {
close(SHTTY);
SHTTY = -1;
--- 1681,1688 ----
} else
setpgrp(0L, jobtab[thisjob].gleader);
}
! if (!fake)
! subsh = 1;
if (SHTTY != -1) {
close(SHTTY);
SHTTY = -1;
***************
*** 1929,1938 ****
return NULL;
}
child_unblock();
- subsh = 1;
close(pipes[0]);
redup(pipes[1], 1);
! entersubsh(Z_SYNC, 1);
signal_ignore(SIGTSTP);
execlist(list, 1);
close(1);
--- 1936,1944 ----
return NULL;
}
child_unblock();
close(pipes[0]);
redup(pipes[1], 1);
! entersubsh(Z_SYNC, 1, 0);
signal_ignore(SIGTSTP);
execlist(list, 1);
close(1);
***************
*** 2028,2036 ****
}
return nam;
}
- subsh = 1;
close(1);
! entersubsh(Z_SYNC, 1);
signal_ignore(SIGTSTP);
(void)creat(nam, 0600);
execlist(list, 1);
--- 2034,2041 ----
}
return nam;
}
close(1);
! entersubsh(Z_SYNC, 1, 0);
signal_ignore(SIGTSTP);
(void)creat(nam, 0600);
execlist(list, 1);
***************
*** 2096,2102 ****
popheap();
return pnam;
}
! entersubsh(Z_ASYNC, 1);
closem();
fd = open(pnam, O_WRONLY);
if (fd == -1) {
--- 2101,2107 ----
popheap();
return pnam;
}
! entersubsh(Z_ASYNC, 1, 0);
closem();
fd = open(pnam, O_WRONLY);
if (fd == -1) {
***************
*** 2148,2154 ****
popheap();
return pnam;
}
! entersubsh(Z_ASYNC, 1);
closem();
fd = open(pnam, O_RDONLY);
redup(fd, 0);
--- 2153,2159 ----
popheap();
return pnam;
}
! entersubsh(Z_ASYNC, 1, 0);
closem();
fd = open(pnam, O_RDONLY);
redup(fd, 0);
***************
*** 2182,2188 ****
}
close(pipes[0]);
closem();
! entersubsh(Z_ASYNC, 1);
redup(pipes[1], 1);
execlist(list, 1);
_exit(lastval);
--- 2187,2193 ----
}
close(pipes[0]);
closem();
! entersubsh(Z_ASYNC, 1, 0);
redup(pipes[1], 1);
execlist(list, 1);
_exit(lastval);
***************
*** 2213,2219 ****
return pipes[1];
}
close(pipes[1]);
! entersubsh(Z_ASYNC, 1);
redup(pipes[0], 0);
closem();
execlist(list, 1);
--- 2218,2224 ----
return pipes[1];
}
close(pipes[1]);
! entersubsh(Z_ASYNC, 1, 0);
redup(pipes[0], 0);
closem();
execlist(list, 1);
--
Peter Stephenson <pws@ifh.de> Tel: +49 33762 77366
WWW: http://www.ifh.de/~pws/ Fax: +49 33762 77330
Deutches Electronen-Synchrotron --- Institut fuer Hochenergiephysik Zeuthen
DESY-IfH, 15735 Zeuthen, Germany.
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1995-11-08 9:22 better subshell patch Peter William Stephenson
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