Re: [patch] replacing "/dev/root" in /proc/mounts
Wakko Warner (wakko@animx.eu.org)
Fri, 8 Oct 1999 12:17:31 -0400
> > |> #include <stdio.h>
> > |> #include <sys/stat.h>
> > |> #include <unistd.h>
> > |> int main(int argc, char **argv)
> > |> {
> > |> struct stat statBuf;
> > |> unsigned int major, minor;
> > |> stat("/", &statBuf);
> > |> major=minor=statBuf.st_dev;
> > |> printf("/ is on device major %d, minor %d\n",
> > |> major>>8, minor&0xff);
> >
> > This is bad, you should be using the major and minor macros.
>
> Right.
>
> I was guessing how Wakko might have written a stat based app, and then I
> go on to say this violates the interface by peeking under the kernel's
> skirt. I had already checked, and the MAJOR and MINOR macros in kdev_t.h
> are wrapped up an inside #ifdef __KERNEL__, and so are not available to
> user space. User space simply has no way of knowing what a dev_t might
> be.
And as the program is right now, it also works on solaris 2.6 (or 2.5, I
can't remember which it was). It doesn't get the /dev/* names right since
it doesn't recurse, but other than that, no problems. It works w/o problems
on linux sparc as well.
--
Lab tests show that use of micro$oft causes cancer in lab animals
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