From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <3C4EA4FC.A777CA4D@strakt.com>
From: Boyd Roberts <boyd@strakt.com>
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To: "9fans@cse.psu.edu" <9fans@cse.psu.edu>
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Subject: [9fans] isatty
Date: Wed, 23 Jan 2002 12:56:44 +0100
Topicbox-Message-UUID: 41df06b0-eaca-11e9-9e20-41e7f4b1d025

Given I had to implement this 'thing' on Plan 9 I decided on:

#include <u.h>
#include <libc.h>

static char *cons = "/dev/cons";

/*
 * Compare fd to cons should get it right.
 */
int
isatty(int fd)
{
	Dir c;
	Dir f;

	if (dirstat(cons, &c) != 0)
		return 0;

	if (dirfstat(fd, &f) != 0)
		return 0;

	return f.type == c.type &&
		f.dev == c.dev &&
		f.qid.path == c.qid.path &&
		f.qid.vers == c.qid.vers;
}

Seemed obvious to me, but is this a good plan?

The overkill on the multiple dirstat's on /dev/cons and
qid comparison I thought would ensure that I wouldn't
get fooled [again].