usr/src/usr.bin/pascal/libpc/UNSYNC.c

/*-
 * Copyright (c) 1979 The Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
static char sccsid[] = "@(#)UNSYNC.c    1.5 (Berkeley) %G%";
#endif /* not lint */

#include "h00vars.h"

/*
 * push back last char read to prepare for formatted read
 */
UNSYNC(curfile)

        register struct iorec   *curfile;
{
        if (curfile->funit & FWRITE) {
                ERROR("%s: Attempt to read, but open for writing\n",
                        curfile->pfname);
                return;
        }
        if (curfile->funit & EOFF) {
                ERROR("%s: Tried to read past end of file\n", curfile->pfname);
                return;
        }
        if ((curfile->funit & SYNC) == 0) {
                ungetc(*curfile->fileptr, curfile->fbuf);
        }
        curfile->funit &= ~EOLN;
        curfile->funit |= SYNC;
}