StdLib/LibC/Uefi/writev.c

/** @file
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 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
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 * 3. All advertising materials mentioning features or use of this software must
 *    display the following acknowledgement:
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 *    This product includes software developed by Intel Corporation and its
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/*++

Module Name:

    writev.c

Abstract:

    Functions implementing the standard "writev" system call interface


Revision History

--*/
#include  <LibConfig.h>

#ifdef foo
#include <efi_interface.h>
#include <unistd.h>
#include <fcntl.h>
#define KERNEL
#include <errno.h>
#undef KERNEL
#include "./filedesc.h"

#include <libc_debug.h>
#include <assert.h>
#endif

#include <stdlib.h>
#include <unistd.h>
#include <sys/uio.h>
#include <string.h>
#ifndef KERNEL
#define KERNEL
#include <errno.h>
#undef KERNEL
#else
#include <errno.h>
#endif

//
//  Name:
//      writev
//
//  Description:
//      BSD writev interface for libc
//
//  Arguments:
//      File Descriptor (index into file descriptor table)
//      iovec pointer
//      size of iovec array
//
//  Returns:
//      number of bytes written
//

ssize_t
writev(
    int fd,
    const struct iovec *iov,
    int iovcnt
    )
{
  const struct iovec   *pVecTmp;
  char                 *pBuf;
  size_t                TotalBytes;
  size_t                i;
  size_t                ret;

  //
  //  See how much memory we'll need
  //

  for (i = 0, TotalBytes = 0, pVecTmp = iov; i < (size_t)iovcnt; i++, pVecTmp++) {
    TotalBytes += pVecTmp->iov_len;
  }

  //
  //  Allocate a contiguous buffer
  //

  pBuf = (char*)malloc (TotalBytes);
  if (pBuf == NULL) {
    errno = ENOMEM;
    return -1;
  }

  //
  //  Copy vectors to the buffer
  //

  for (; iovcnt; iovcnt--) {
    bcopy(iov->iov_base, pBuf, iov->iov_len);
    pBuf += iov->iov_len;
    iov++;
  }

  //
  //  Use standard write(2) then free buffer
  //

  ret = write (fd, pBuf, TotalBytes);
  free (pBuf);

  return (ret);
}