Re: [dwm] dwm-5.3

On Sat, 6 Dec 2008 19:38:16 +0100
Guillaume Quintin <coincoin169g_AT_gmail.com> wrote:

> On Sat, 6 Dec 2008 19:20:58 +0100
> Guillaume Quintin <coincoin169g_AT_gmail.com> wrote:
>
> > On Sat, 06 Dec 2008 09:26:25 -0700
> > Neale Pickett <neale_AT_woozle.org> wrote:
> >
> > > Jeremy Jay <dinkumator_AT_gmail.com> writes:
> > >
> > > > This was my hunch too, glad someone got it before me though.
> > > > This patch fixes the problem with 5.3. Probably the same with
> > > > the double- fork version too.
> > >
> > > The open FD was my first guess too, but the double-fork version
> > > didn't close any fds either, so I assumed it must be something
> > > else.
> > >
> > > Guillaume, if you apply the "close(0)" patch, does the problem go
> > > away?
> > >
> > > I'm away from my dwm computer right now, or I'd try it myself.
> > >
> > > Neale
> > >
> >
> > I just tried the close(0) patch but it does not change anything.
> > And I found something very weird. I told you that in the previous
> > version of dwm (5.2) with the .xinitrc containing the "while | dwm"
> > all worked fine and I am sure of that. I quitted dwm-5.2 many times
> > with a lot of openned windows and all worked fine. But now, when I
> > reinstall dwm-5.2 I get the same problem than in dwm-5.3 and
> > dwm-5.3.1, "double-fork", "simple-fork" and re-"double-fork". I
> > don't understand why.
> >
> > Why don't we change the way dwm gets its status text ? For example
> > we could use the SIGALRM signal to call a "spawn2" :
> >
> > spawn2()
> > {
> > check for a certain shell script ".dwmstatus";
> > if it is not present then return;
> > create some pipe p[];
> > (double or simple)-fork;
> > in the child process
> > {
> > close(0);
> > close(1);
> > close(2);
> > set stdout to p[1]; /* I don't know how exactly */
> > execv(".dwmstatus");
> > }
> > /* Here is dwm */
> > read status from p[0];
> > display status;
> > }
> >
> > This will take only a few LOC, because all the reading p[0] part
> > will be in fact the reading-stdin code from the run() function which
> > will not be needed anymore. This has the advantages that one can
> > change the status when dwm is running and there are no more
> > "quitting" problem. This is just an idea, forgive me not to propose
> > some real code. Well tell me what you think of this idea.
> >
>
> This is more simple with the popen() function. We could simply get the
> shell commands to execute from the arguments passed to dwm or read
> them from any file or from stdin only once.
>

This is a little very basic patch that does what I asked above. I tried
this using the SIGALRM signal but I "randomly" got fatal errors about
memory (un)locks.

I have a dwmstatus script :

~/.dwmstatus
#!/bin/sh
date

and my .xinitrc is :

~/.xinitrc
exec dwm -s ./dwmstatus

And every second I get the status bar text updated. Tell me what you
think about it.

-- 
Kind regards,
Guillaume Quintin.