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From: boyd@necisa.ho.necisa.oz (Boyd Roberts)
Newsgroups: comp.unix.wizards
Subject: Re: A question on the implementation of /dev/stdin, etc.
Message-ID: <1706@necisa.ho.necisa.oz>
Date: 7 May 90 23:44:22 GMT
References: <6148.262dbb8d@csv.viccol.edu.au> <707@ehviea.ine.philips.nl> <[2643142a:635.16]comp.unix.wizards;1@wcbcs>
Organization: NEC Information Systems Australia Pty. Ltd.
Lines: 34

In article <[2643142a:635.16]comp.unix.wizards;1@wcbcs> akcs.kevin@wcbcs (Kevin Schoedel) writes:
>This discussion has prompted me to try to implement /dev/fd/... for
>System V 3.2 on a 386.  I don't have kernel source, so I can't use the
>   case IFCHR:

Yes, do it as a device driver.  But...  you'll have to cheat!

Grody hack follows:

    fdopen(dev, mode)
    dev_t   dev;
    int	    mode;
    {
	/* u_rval1 should hold the allocated file descriptor -- gag! */

	closef(u.u_ofile[u.u_rval1]);

	if (u.u_error)
	    return;

	if (u.u_ofile[minor(dev)] != NULL)
	{
	    /* fake dup */
	    u.u_ofile[u.u_rval1] = u.u_ofile[minor(dev)];
	    u.u_ofile[minor(dev)]->f_count++;
	}
	else
	    u.u_error = EBADF;
    }


Boyd Roberts			boyd@necisa.ho.necisa.oz.au

``When the going gets wierd, the weird turn pro...''