ttygetc.c,v

来自「TCP-IP红宝书源代码」· C,V 代码 · 共 89 行

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date	97.09.21.19.30.23;	author dls;	state Dist;
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date	94.05.08.06.01.42;	author dls;	state Old;
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@/* ttygetc.c - ttygetc */

#include <conf.h>
#include <kernel.h>
#include <tty.h>

/*------------------------------------------------------------------------
 * ttygetc - read a single character from a tty
 *------------------------------------------------------------------------
 */
int
ttygetc(pdev)
struct devsw	*pdev;
{
	unsigned char	ch;
	int		cc;

	cc = ttyread(pdev, &ch, 1);
	if (cc < 0)
		return SYSERR;
	else if (cc == 0)
		return EOF;
	return ch;
}
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@Initial revision
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#include <io.h>
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 *  ttygetc - read one character from a tty device
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ttygetc(devptr)
struct	devsw	*devptr;
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	STATWORD ps;    
	int	ch;
	struct	tty   *iptr;
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	disable(ps);
	iptr = &tty[devptr->dvminor];
	wait(iptr->isem);		/* wait	for a character	in buff	*/
	ch = LOWBYTE & iptr->ibuff[iptr->itail++];
	--iptr->icnt;
	if (iptr->itail	>= IBUFLEN)
		iptr->itail = 0;
	if (iptr->ieof && (iptr->ieofc == ch) )
		ch = EOF;
	restore(ps);
	return(ch);
@