full_read.c

来自「这是一个SIGMA方案的PMP播放器的UCLINUX程序,可播放DVD,VCD,」· C语言 代码 · 共 65 行

/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Copyright (C) 1999,2000,2001 by Erik Andersen <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <stdio.h>
#include <unistd.h>
#include "libbb.h"


/*
 * Read all of the supplied buffer from a file.
 * This does multiple reads as necessary.
 * Returns the amount read, or -1 on an error.
 * A short read is returned on an end of file.
 */
int full_read(int fd, char *buf, int len)
{
	int cc;
	int total;

	total = 0;

	while (len > 0) {
		cc = read(fd, buf, len);

		if (cc < 0)
			return -1;

		if (cc == 0)
			break;

		buf += cc;
		total += cc;
		len -= cc;
	}

	return total;
}

/* END CODE */
/*
Local Variables:
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/