From mboxrd@z Thu Jan  1 00:00:00 1970
From: erik quanstrom <quanstro@quanstro.net>
Date: Wed, 19 Sep 2012 09:35:51 -0400
To: 9fans@9fans.net
Message-ID: <18674d790afd2a7602091b8d8e704712@brasstown.quanstro.net>
In-Reply-To: <22e43e02e32dd37beb7f8c52105e45b6@quintile.net>
References: <22e43e02e32dd37beb7f8c52105e45b6@quintile.net>
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Subject: Re: [9fans] Brdline() and continuation lines
Topicbox-Message-UUID: ba4e5ada-ead7-11e9-9d60-3106f5b1d025

> Anyone worked out an idiom that would allow me to
> use Brdline()/Blinelen() to read a file which
> contains continuation lines?
>
> I want to read a text file which consists of lines terminated
> by newlines, but lines with leading whitespace are considered
> to be continuation lines.
>
> Brdline() is very neat allowing me to parse input lines inside the
> Biobuf buffer without copying them to "user space", however if I
> do a Brdline(), get a line and then attempt to do another Brdline()
> I am in danger of releaseing the buffer space used by the first read.
>
> I am happy if the answer is "Brdline() cannot do this", I just feel like
> I am missing a trick, and there is elegant solution.

/*
 * Bgetrune seems like overkill, but avoids passing up bad runes.
 */
int
Brdlinec(Biobuf *b, char *s, char *e)
{
	char *p;
	int x, slash;
	Rune r;

	for(p = s; e-p > UTFmax+1;){
		x = Bgetrune(b);
		if(x == -1)
			return -1;
		r = x;
		if(r == '\\'){
			x = Bgetrune(b);
			if(x == -1)
				return -1;
			if(x == '\n')
				continue;
			p += runetochar(p, &r);
			r = x;
		}else if(r == '\n')
			break;
		p += runetochar(p, r);
	}
	*p = 0;
	return p-e;
}