usr/src/cmd/sendmail/libsm/fpurge.c

   1 /*
   2  * Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers.
   3  *      All rights reserved.
   4  * Copyright (c) 1990, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Chris Torek.
   9  *
  10  * By using this file, you agree to the terms and conditions set
  11  * forth in the LICENSE file which can be found at the top level of
  12  * the sendmail distribution.
  13  */
  14
  15 #pragma ident   "%Z%%M% %I%     %E% SMI"
  16
  17 #include <sm/gen.h>
  18 SM_RCSID("@(#)$Id: fpurge.c,v 1.18 2001/01/28 00:29:35 ca Exp $")
  19 #include <stdlib.h>
  20 #include <errno.h>
  21 #include <sm/io.h>
  22 #include <sm/assert.h>
  23 #include "local.h"
  24
  25 /*
  26 **  SM_IO_PURGE -- purge/empty the buffer without committing buffer content
  27 **
  28 **      Parameters:
  29 **              fp -- file pointer to purge
  30 **
  31 **      Returns:
  32 **              Failure: returns SM_IO_EOF and sets errno
  33 **              Success: returns 0 (zero)
  34 */
  35
  36 int
  37 sm_io_purge(fp)
  38         register SM_FILE_T *fp;
  39 {
  40         SM_REQUIRE_ISA(fp, SmFileMagic);
  41         if (!fp->f_flags)
  42         {
  43                 errno = EBADF;
  44                 return SM_IO_EOF;
  45         }
  46
  47         if (HASUB(fp))
  48                 FREEUB(fp);
  49         fp->f_p = fp->f_bf.smb_base;
  50         fp->f_r = 0;
  51
  52         /* implies SMFBF */
  53         fp->f_w = fp->f_flags & (SMLBF|SMNBF) ? 0 : fp->f_bf.smb_size;
  54         return 0;
  55 }