contrib/sendmail-8.13.7/libsm/fwrite.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: fwrite.c,v 1.24 2001/09/11 04:04:48 gshapiro Exp $")
  17 #include <errno.h>
  18 #include <sm/io.h>
  19 #include <sm/assert.h>
  20 #include "local.h"
  21 #include "fvwrite.h"
  22
  23 /*
  24 **  SM_IO_WRITE -- write to a file pointer
  25 **
  26 **      Parameters:
  27 **              fp -- file pointer writing to
  28 **              timeout -- time to complete the write
  29 **              buf -- location of data to be written
  30 **              size -- number of bytes to be written
  31 **
  32 **      Result:
  33 **              Failure: returns 0 _and_ sets errno
  34 **              Success: returns >=0 with errno unchanged, where the
  35 **                      number returned is the number of bytes written.
  36 */
  37
  38 size_t
  39 sm_io_write(fp, timeout, buf, size)
  40         SM_FILE_T *fp;
  41         int timeout;
  42         const void *buf;
  43         size_t size;
  44 {
  45         struct sm_uio uio;
  46         struct sm_iov iov;
  47
  48         SM_REQUIRE_ISA(fp, SmFileMagic);
  49
  50         if (fp->f_write == NULL)
  51         {
  52                 errno = ENODEV;
  53                 return 0;
  54         }
  55
  56         iov.iov_base = (void *) buf;
  57         uio.uio_resid = iov.iov_len = size;
  58         uio.uio_iov = &iov;
  59         uio.uio_iovcnt = 1;
  60
  61         /* The usual case is success (sm_fvwrite returns 0) */
  62         if (sm_fvwrite(fp, timeout, &uio) == 0)
  63                 return size;
  64
  65         /* else return number of bytes actually written */
  66         return size - uio.uio_resid;
  67 }