contrib/sendmail-8.14/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 #include <sm/gen.h>
  16 SM_RCSID("@(#)$Id: fpurge.c,v 1.20 2001/09/11 04:04:48 gshapiro Exp $")
  17 #include <stdlib.h>
  18 #include <errno.h>
  19 #include <sm/io.h>
  20 #include <sm/assert.h>
  21 #include "local.h"
  22
  23 /*
  24 **  SM_IO_PURGE -- purge/empty the buffer without committing buffer content
  25 **
  26 **      Parameters:
  27 **              fp -- file pointer to purge
  28 **
  29 **      Returns:
  30 **              Failure: returns SM_IO_EOF and sets errno
  31 **              Success: returns 0 (zero)
  32 */
  33
  34 int
  35 sm_io_purge(fp)
  36         register SM_FILE_T *fp;
  37 {
  38         SM_REQUIRE_ISA(fp, SmFileMagic);
  39         if (!fp->f_flags)
  40         {
  41                 errno = EBADF;
  42                 return SM_IO_EOF;
  43         }
  44
  45         if (HASUB(fp))
  46                 FREEUB(fp);
  47         fp->f_p = fp->f_bf.smb_base;
  48         fp->f_r = 0;
  49
  50         /* implies SMFBF */
  51         fp->f_w = fp->f_flags & (SMLBF|SMNBF) ? 0 : fp->f_bf.smb_size;
  52         return 0;
  53 }