usr/src/usr.lib/libU77/ftell_.c

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *      @(#)ftell_.c    5.1     6/7/85
 */

/*
 * return current file position
 *
 * calling sequence:
 *      integer curpos, ftell
 *      curpos = ftell(lunit)
 * where:
 *      lunit is an open logical unit
 *      curpos will be the current offset in bytes from the start of the
 *              file associated with that logical unit
 *              or a (negative) system error code.
 */

#include        "../libI77/fiodefs.h"
#include        "../libI77/f_errno.h"

extern unit units[];

long ftell_(lu)
long *lu;
{
        if (*lu < 0 || *lu >= MXUNIT)
                return(-(long)(errno=F_ERUNIT));
        if (!units[*lu].ufd)
                return(-(long)(errno=F_ERNOPEN));
        return(ftell(units[*lu].ufd));
}