StdLib/LibC/Uefi/writev.c

   1 /** @file
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   3  * Copyright (c) 1999 - 2014, Intel Corporation. All rights reserved.<BR>
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  37
  38 /*++
  39
  40 Module Name:
  41
  42     writev.c
  43
  44 Abstract:
  45
  46     Functions implementing the standard "writev" system call interface
  47
  48
  49 Revision History
  50
  51 --*/
  52 #include  <LibConfig.h>
  53
  54 #ifdef foo
  55 #include <efi_interface.h>
  56 #include <unistd.h>
  57 #include <fcntl.h>
  58 #define KERNEL
  59 #include <errno.h>
  60 #undef KERNEL
  61 #include "./filedesc.h"
  62
  63 #include <libc_debug.h>
  64 #include <assert.h>
  65 #endif
  66
  67 #include <stdlib.h>
  68 #include <unistd.h>
  69 #include <sys/uio.h>
  70 #include <string.h>
  71 #ifndef KERNEL
  72 #define KERNEL
  73 #include <errno.h>
  74 #undef KERNEL
  75 #else
  76 #include <errno.h>
  77 #endif
  78
  79 //
  80 //  Name:
  81 //      writev
  82 //
  83 //  Description:
  84 //      BSD writev interface for libc
  85 //
  86 //  Arguments:
  87 //      File Descriptor (index into file descriptor table)
  88 //      iovec pointer
  89 //      size of iovec array
  90 //
  91 //  Returns:
  92 //      number of bytes written
  93 //
  94
  95 ssize_t
  96 writev(
  97     int fd,
  98     const struct iovec *iov,
  99     int iovcnt
 100     )
 101 {
 102   const struct iovec   *pVecTmp;
 103   char                 *pBuf;
 104   size_t                TotalBytes;
 105   size_t                i;
 106   size_t                ret;
 107
 108   //
 109   //  See how much memory we'll need
 110   //
 111
 112   for (i = 0, TotalBytes = 0, pVecTmp = iov; i < (size_t)iovcnt; i++, pVecTmp++) {
 113     TotalBytes += pVecTmp->iov_len;
 114   }
 115
 116   //
 117   //  Allocate a contiguous buffer
 118   //
 119
 120   pBuf = (char*)malloc (TotalBytes);
 121   if (pBuf == NULL) {
 122     errno = ENOMEM;
 123     return -1;
 124   }
 125
 126   //
 127   //  Copy vectors to the buffer
 128   //
 129
 130   for (; iovcnt; iovcnt--) {
 131     bcopy(iov->iov_base, pBuf, iov->iov_len);
 132     pBuf += iov->iov_len;
 133     iov++;
 134   }
 135
 136   //
 137   //  Use standard write(2) then free buffer
 138   //
 139
 140   ret = write (fd, pBuf, TotalBytes);
 141   free (pBuf);
 142
 143   return (ret);
 144 }