incpt.c

Minix比较全的源码

/* $Header$ */
/*
 * (c) copyright 1983 by the Vrije Universiteit, Amsterdam, The Netherlands.
 *
 *          This product is part of the Amsterdam Compiler Kit.
 *
 * Permission to use, sell, duplicate or disclose this software must be
 * obtained in writing. Requests for such permissions may be sent to
 *
 *      Dr. Andrew S. Tanenbaum
 *      Wiskundig Seminarium
 *      Vrije Universiteit
 *      Postbox 7161
 *      1007 MC Amsterdam
 *      The Netherlands
 *
 */

/* Author: J.W. Stevenson */

#include	<pc_file.h>
#include	<pc_err.h>

#define EINTR	4

extern int	errno;
extern		_trp();
extern int	_read();

_incpt(f) struct file *f; {

	if (f->flags & EOFBIT)
		_trp(EEOF);
	f->flags |= WINDOW;
	f->flags &= ~ELNBIT;
#ifdef CPM
	do {
#endif
	f->ptr += f->size;
	if (f->count == 0) {
		f->ptr = f->bufadr;
		for(;;) {
			f->count=_read(f->ufd,f->bufadr,f->buflen);
			if ( f->count<0 ) {
				if (errno != EINTR) _trp(EREAD) ;
				continue ;
			}
			break ;
		}
		if (f->count == 0) {
			f->flags |= EOFBIT;
			*f->ptr = '\0';
			return;
		}
	}
	if ((f->count -= f->size) < 0)
		_trp(EFTRUNC);
#ifdef CPM
	} while ((f->flags&TXTBIT) && *f->ptr == '\r');
#endif
	if (f->flags & TXTBIT) {
		if (*f->ptr & 0200)
			_trp(EASCII);
		if (*f->ptr == '\n') {
			f->flags |= ELNBIT;
			*f->ptr = ' ';
		}
#ifdef CPM
		if (*f->ptr == 26) {
			f->flags |= EOFBIT;
			*f->ptr = 0;
		}
#endif
	}
}