[src/trunk]: src/distrib/utils/sysinst provide a way to ignore tty-generated ...

[cgd <cgd%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/3786373af914
branches:  trunk
changeset: 473918:3786373af914
user:      cgd <cgd%NetBSD.org@localhost>
date:      Tue Jun 22 00:43:57 1999 +0000

description:
provide a way to ignore tty-generated signals (INTR and QUIT) and/or
forward them on to subprocesses.  nice when running a subprocess in
a display window to allow the user to kill the subprocess w/o nuking
sysinst itself.  add handling for QUIT, which gets handled the same
as intr.  add handling for HUP which just cleans up.  More signals
should be handled.

diffstat:

 distrib/utils/sysinst/defs.h |   4 ++-
 distrib/utils/sysinst/main.c |  45 ++++++++++++++++++++++++++++++++++++++-----
 distrib/utils/sysinst/run.c  |  21 ++++++++++++++++++-
 3 files changed, 61 insertions(+), 9 deletions(-)

diffs (161 lines):

diff -r bb55bdee7ef6 -r 3786373af914 distrib/utils/sysinst/defs.h
--- a/distrib/utils/sysinst/defs.h      Mon Jun 21 22:31:32 1999 +0000
+++ b/distrib/utils/sysinst/defs.h      Tue Jun 22 00:43:57 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: defs.h,v 1.42 1999/06/20 06:08:13 cgd Exp $    */
+/*     $NetBSD: defs.h,v 1.43 1999/06/22 00:43:57 cgd Exp $    */
 
 /*
  * Copyright 1997 Piermont Information Systems Inc.
@@ -91,6 +91,8 @@
 
 EXTERN int yesno;
 EXTERN int ignorerror;
+EXTERN int ttysig_ignore;
+EXTERN pid_t ttysig_forward;
 EXTERN int layoutkind;
 EXTERN int sizemult INIT(1);
 EXTERN char *multname; 
diff -r bb55bdee7ef6 -r 3786373af914 distrib/utils/sysinst/main.c
--- a/distrib/utils/sysinst/main.c      Mon Jun 21 22:31:32 1999 +0000
+++ b/distrib/utils/sysinst/main.c      Tue Jun 22 00:43:57 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: main.c,v 1.17 1999/06/20 06:08:14 cgd Exp $    */
+/*     $NetBSD: main.c,v 1.18 1999/06/22 00:43:57 cgd Exp $    */
 
 /*
  * Copyright 1997 Piermont Information Systems Inc.
@@ -56,7 +56,8 @@
 
 int main __P((int argc, char **argv));
 static void usage __P((void));
-static void inthandler __P((int));
+static void miscsighandler __P((int));
+static void ttysighandler __P((int));
 static void cleanup __P((void));
 static void process_f_flag __P((char *));
 
@@ -125,9 +126,11 @@
        }
                msg_window(win);
 
-       /* Watch for SIGINT and clean up */
-       (void)signal(SIGINT, inthandler);
+       /* Watch for signals and clean up */
        (void)atexit(cleanup);
+       (void)signal(SIGINT, ttysighandler);
+       (void)signal(SIGQUIT, ttysighandler);
+       (void)signal(SIGHUP, miscsighandler);
 
        /* Menu processing */
        process_menu(MENU_netbsd);
@@ -167,11 +170,41 @@
 
 /* ARGSUSED */
 static void
-inthandler(notused)
-       int notused;
+miscsighandler(signo)
+       int signo;
+{
+
+       /*
+        * we need to cleanup(), but it was already scheduled with atexit(),
+        * so it'll be invoked on exit().
+        */
+       exit(1);
+}
+
+static void
+ttysighandler(signo)
+       int signo;
 {
 
        /*
+        * if we want to ignore a TTY signal (SIGINT or SIGQUIT), then we
+        * just return.  If we want to forward a TTY signal, we forward it
+        * to the specified process group.
+        *
+        * This functionality is used when setting up and displaying child
+        * output so that the child gets the signal and presumably dies,
+        * but sysinst continues.  We use this rather than actually ignoring
+        * the signals, because that will be be passed on to a child
+        * through fork/exec, whereas special handlers get reset on exec..
+        */
+       if (ttysig_ignore)
+               return;
+       if (ttysig_forward) {
+               killpg(ttysig_forward, signo);
+               return;
+       }
+
+       /*
         * we need to cleanup(), but it was already scheduled with atexit(),
         * so it'll be invoked on exit().
         */
diff -r bb55bdee7ef6 -r 3786373af914 distrib/utils/sysinst/run.c
--- a/distrib/utils/sysinst/run.c       Mon Jun 21 22:31:32 1999 +0000
+++ b/distrib/utils/sysinst/run.c       Tue Jun 22 00:43:57 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: run.c,v 1.20 1999/06/21 02:55:27 cgd Exp $     */
+/*     $NetBSD: run.c,v 1.21 1999/06/22 00:43:57 cgd Exp $     */
 
 /*
  * Copyright 1997 Piermont Information Systems Inc.
@@ -287,8 +287,12 @@
        rtt.c_lflag &= ~ECHO; 
        (void)tcsetattr(STDIN_FILENO, TCSAFLUSH, &rtt);
 
+       /* ignore tty signals until we're done with subprocess setup */
+       ttysig_ignore = 1;
+
        switch(child=fork()) {
        case -1:
+               ttysig_ignore = 0;
                return -1;
                break;
        case 0:
@@ -325,7 +329,13 @@
                warn("execvp %s", argzero);
                _exit(EXIT_FAILURE);
                break; /* end of child */
-       default: break;
+       default:
+               /*
+                * we've set up the subprocess.  forward tty signals to its                      * process group.
+                */
+               ttysig_forward = child;
+               ttysig_ignore = 0;
+               break;
        }
        close(dataflow[1]);
        FD_ZERO(&active_fd_set);
@@ -342,6 +352,8 @@
                }
                read_fd_set = active_fd_set;
                if (select(FD_SETSIZE, &read_fd_set, NULL, NULL, NULL) < 0) {
+                       if (errno == EINTR)
+                               goto loop;
                        perror("select");
                        if (logging)
                                (void)fprintf(log, "select failure: %s\n", strerror(errno));
@@ -376,6 +388,7 @@
                                }
                        }
                }
+loop:
                pid = wait4(child, &status, WNOHANG, 0);
                if (pid == child && (WIFEXITED(status) || WIFSIGNALED(status)))
                        break;
@@ -386,7 +399,11 @@
        if (logging)
                fflush(log);
 
+       /* from here on out, we take tty signals ourselves */
+       ttysig_forward = 0;
+
        (void)tcsetattr(STDIN_FILENO, TCSAFLUSH, &tt);
+
        if (WIFEXITED(status))
                return(WEXITSTATUS(status));
        else if (WIFSIGNALED(status))