[9fans] bungetc error

[9fans] bungetc error

[smahapatra_ct]

I think after bgetc returns Beof, bungetc should change the state, but
not decrement bp->icount.

The correct code should be:

int
Bungetc(Biobufhdr *bp)
{
        if(bp->state != Bractive) {
                if (bp->state == Bracteof)
                         bp->state = Bractive;
                return Beof;
        }
	bp->icount--;
	return 1;
}

instead of the current code:

int
Bungetc(Biobufhdr *bp)
{

	if(bp->state == Bracteof)
		bp->state = Bractive;
	if(bp->state != Bractive)
		return Beof;
	bp->icount--;
	return 1;
}

Regards,
Saroj Mahapatra

Re: [9fans] bungetc error

[Martin Neubauer]

* smahapatra_ct@yahoo.com (smahapatra_ct@yahoo.com) wrote:
> I think after bgetc returns Beof, bungetc should change the state, but
> not decrement bp->icount.

I don't think so. Bungetc ungets the last character read, not Beof.

Re: [9fans] bungetc error

[Charles Forsyth]

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i assumed the intention was:
in practice it's sometimes a nuisance to have to keep a flag in the
application to say whether eof has been reached or not,
when it could be done by allowing an unget at eof.

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From: Martin Neubauer <m.ne@gmx.net>
To: Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu>
Subject: Re: [9fans] bungetc error
Date: Wed, 2 Jan 2008 22:51:28 +0100
Message-ID: <20080102215128.GB810@shodan.homeunix.net>

* smahapatra_ct@yahoo.com (smahapatra_ct@yahoo.com) wrote:
> I think after bgetc returns Beof, bungetc should change the state, but
> not decrement bp->icount.

I don't think so. Bungetc ungets the last character read, not Beof.