On Fri, Oct 29, 2021 at 08:18:43AM -0600, Theo de Raadt wrote:
> Please don't do this.
Agreed. Please don't add such quirks to bend over backwards for pagers
that misbehave.
> Ingo Schwarze <schwa...@usta.de> wrote:
>
> > Hi Stuart,
> >
> > Stuart Henderson wrote on Fri, Oct 29, 2021 at 01:59:38PM +0100:
> > > On 2021/10/29 14:08, Ingo Schwarze wrote:
> > >> Stuart Henderson wrote on Fri, Oct 29, 2021 at 10:53:41AM +0100:
> > >>> On 2021/10/28 23:19, Klemens Nanni wrote:
> > >>>> On Fri, Oct 29, 2021 at 12:57:54AM +0200, Ingo Schwarze wrote:
> >
> > >>>>> MANPAGER=firefox man -T html $(ifconfig -C)
> >
> > >>>> This doesn't work if firefox is already running as the MANPAGER firefox
> > >>>> process exits immediately after sending the file/link to the running
> > >>>> process, which causes mandoc to exit after removing the temporary file,
> > >>>> by which time firefox fails to open the no longer exiting file.
> >
> > >>> I use mutt_bgrun for things like this
> >
> > >> I don't see how that can possibly help.
> >
> > > Oh, of course you're right - I was confused between my helper
> > > scripts. The one I actually use for html in mutt looks like this,
> > > so it's not any user for MANPAGER..
> > >
> > > tmp=`mktemp -d /tmp/mutthtml.XXXXXXXXX` || exit 1
> > > mhonarc -rcfile ~/.m2h_rcfile -single > $tmp/mail.html
> > > (chrome $tmp/mail.html 2>/dev/null; sleep 30; rm -r $tmp) &
> >
> > Indeed, if i added sleep(30) to the place in question
> > in usr.bin/mandoc/main.c, i would expect quite an outrage...
> > A protest rally on my front lawn or something like that...
> >
> > Then again, the man(1) process that is about to exit could maybe fork
> > a child before exiting. The parent exiting right away makes sure that
> > the user gets back their shell prompt instantly after exiting the pager.
> > The child process, now being in the background, could sleep a few seconds
> > before deleting the temporary output files, then exit, too.
> >
> > This does appear to successfully work around the firefox bug.
> > With the patch below, "MANPAGER=firefox man -T html ..."
> > now works reliably for me.
> >
> > It does seem somewhat ugly, though, so i'm not sure whether i should
> > commit it. In particular, fork(2)ing merely to go to the background
> > seems both cumbersome and expensive - admittedly, your script cited
> > above does the same, but that doesn't imply i have to like that, right?
> >
> > Is there a cleaner way to let man(1) go into the background and
> > let the shell offer a fresh prompt while man(1) still sleeps,
> > without needing to fork(2)?
> >
> > Yours,
> > Ingo
> >
> >
> > Index: main.c
> > ===================================================================
> > RCS file: /cvs/src/usr.bin/mandoc/main.c,v
> > retrieving revision 1.262
> > diff -u -p -r1.262 main.c
> > --- main.c 4 Oct 2021 21:28:50 -0000 1.262
> > +++ main.c 29 Oct 2021 14:12:08 -0000
> > @@ -1203,6 +1203,7 @@ woptions(char *arg, enum mandoc_os *os_e
> > static void
> > run_pager(struct outstate *outst, char *tag_target)
> > {
> > + const struct timespec delay = { 5, 0 };
> > int signum, status;
> > pid_t man_pgid, tc_pgid;
> > pid_t pager_pid, wait_pid;
> > @@ -1245,13 +1246,16 @@ run_pager(struct outstate *outst, char *
> > if (wait_pid == -1) {
> > mandoc_msg(MANDOCERR_WAIT, 0, 0,
> > "%s", strerror(errno));
> > - break;
> > + return;
> > }
> > if (!WIFSTOPPED(status))
> > break;
> >
> > signum = WSTOPSIG(status);
> > }
> > + if (fork() > 0)
> > + _exit(mandoc_msg_getrc());
> > + nanosleep(&delay, NULL);
> > }
> >
> > static pid_t
> >
>
