1*46111Sbostic /*- 2*46111Sbostic * Copyright (c) 1990 The Regents of the University of California. 3*46111Sbostic * All rights reserved. 4*46111Sbostic * 5*46111Sbostic * This code is derived from software contributed to Berkeley by 6*46111Sbostic * Chris Torek. 7*46111Sbostic * 8*46111Sbostic * %sccs.include.redist.c% 9*46111Sbostic */ 10*46111Sbostic 11*46111Sbostic #if defined(LIBC_SCCS) && !defined(lint) 12*46111Sbostic static char sccsid[] = "@(#)fpurge.c 5.1 (Berkeley) 01/20/91"; 13*46111Sbostic #endif /* LIBC_SCCS and not lint */ 14*46111Sbostic 15*46111Sbostic #include <errno.h> 16*46111Sbostic #include <stdio.h> 17*46111Sbostic #include "local.h" 18*46111Sbostic 19*46111Sbostic /* 20*46111Sbostic * fpurge: like fflush, but without writing anything: leave the 21*46111Sbostic * given FILE's buffer empty. 22*46111Sbostic */ 23*46111Sbostic int 24*46111Sbostic fpurge(fp) 25*46111Sbostic register FILE *fp; 26*46111Sbostic { 27*46111Sbostic if (!fp->_flags) { 28*46111Sbostic errno = EBADF; 29*46111Sbostic return(EOF); 30*46111Sbostic } 31*46111Sbostic 32*46111Sbostic if (HASUB(fp)) 33*46111Sbostic FREEUB(fp); 34*46111Sbostic fp->_p = fp->_bf._base; 35*46111Sbostic fp->_r = 0; 36*46111Sbostic fp->_w = fp->_flags & (__SLBF|__SNBF) ? 0 : fp->_bf._size; 37*46111Sbostic return (0); 38*46111Sbostic } 39