shithub: scc

ref: d7f0e25b97d041a2645e2d90f6033949b01c7cc6
dir: /src/libc/stdio/fseek.c/

View raw version 
#include <stdio.h>

#include "../syscall.h"
#include "../libc.h"

#undef fseek

int
fseek(FILE *fp, long off, int whence)
{
	if (fp->flags & _IOERR)
		return EOF;

	if ((fp->flags & _IOWRITE) && _flsbuf(fp))
		return -1;
	else if (whence == SEEK_CUR && (fp->flags & _IOREAD))
		off -= fp->wp - fp->rp;

	if (_lseek(fp->fd, off, whence) < 0) {
		fp->flags |= _IOERR;
		return EOF;
	}

	if (fp->flags & _IORW)
		fp->flags &= ~(_IOREAD | _IOWRITE);
	fp->flags &= ~_IOEOF;

	return 0;
}