[BusyBox] bug#1261: BusyBox] bug#1261: Ash holds some extra file descriptors open

[Vladimir N. Oleynik]

Hi, Steve.

> > I not found other opened fd except 0-2 :0
> 
> I take it you compiled this program and ran it as a child process to
> look at the open fds?

Yes.
 
> You won't see it there, as you have found.
> 
> Instead, you have to look at the kernel to see who's holding what
> open.

I rewrote your test and change all "cat" usage to "help" - builting
function ash and hack this with usage my fd_test with your algoritm:

#if DEBUG == 2
static void test_fd (void)
{
        int p, l, i;
        FILE *log;
        static const char nlog[]="/tmp/fd_opened.log";
        char cmd[256];

        log = fopen(nlog, "a");
        if(log==NULL) {
                fprintf(stderr, "can`t create %s\n", nlog);
                return;
        }
        p = getpid();
        strcpy(cmd, "/proc/");
        l = strlen(cmd);
        sprintf(cmd+l, "%d/fd/", p);
        l = strlen(cmd);
        fprintf(log, "pid=%d test opened fd\n", p);
        for(i=0; i<1024; i++) {
                if(i==fileno(log))
                        continue;
                sprintf(cmd+l, "%d", i);
                if(access(cmd, F_OK)==0)
                        fprintf(log, "pid=%d opened fd=%d\n", p, i);
        }
        fclose(log);
}
#endif


I see open 3, 10, 11 fd now. :(

But ash have deferent tread call external and internal process.

> The rules for redirection are: pipes are done first, then redirections
> are done in order from left to right.
> 
> Here's a bit of command line to explain:
> you will find that stderr goes to log2 as you intend, and again, bash
> doesn't pause but busybox ash does.
> 
> Does that help?

Thanks.
Ok. Ok. Ok.
I begining porting ash 0.3.8-38 (last debian ash) to busybox.
All ported done, but all my and other optimizations changes not ready.
Please wait 1-2 week.


--w
vodz