lseek_r.c

来自「FAT16 Filesystem on Philips LPC2000 seri」· C语言 代码 · 共 29 行

#include <reent.h>
#include <errno.h>
#include <devices.h>
#include	<ioctl.h>
#include <sysdefs.h>
#include <iface.h>

_off_t _lseek_r (struct _reent *ptr, int fd, _off_t pos, int whence)
{
#ifdef HAS_MMC
struct IOCTLSEEKSTRUCT {
	_off_t	* pos;
	int		* whence;
} IOCTL_SEEKER;
int	idx;
		// look thru device table for this device.
	if ((idx = find_device (ptr, DEVICE_TYPE(fd))) == -1) return -1;
		// call function if defined.
	if (device_table_list [idx].item->ioctl) {
		IOCTL_SEEKER.pos = &pos;
		IOCTL_SEEKER.whence = &whence;
		return device_table_list [idx].item->ioctl (ptr, fd, IOCTL_MMC_SEEK, &IOCTL_SEEKER);
	}
#endif
	ptr->_errno = EBADF;
	return -1;
}