reactos/lib/crt/io/read.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:   See COPYING in the top level directory
   4  * PROJECT:     ReactOS system libraries
   5  * FILE:        lib/msvcrt/io/read.c
   6  * PURPOSE:     Reads a file
   7  * PROGRAMER:   Ariadne
   8  * UPDATE HISTORY:
   9  *              28/12/1998: Created
  10  *              03/05/2002: made _read() non-greedy - it now returns as soon as
  11  *                          any amount of data has been read. It's the expected
  12  *                          behavior for line-buffered streams (KJK::Hyperion)
  13  */
  14
  15 #include <precomp.h>
  16
  17 #define NDEBUG
  18 #include <internal/debug.h>
  19
  20 /*
  21  * @implemented
  22  */
  23 int _read(int _fd, void *_buf, unsigned int _nbyte)
  24 {
  25    DWORD _rbyte = 0, nbyte = _nbyte;
  26    char *bufp = (char*)_buf;
  27    HANDLE hfile;
  28    int istext, error;
  29
  30    DPRINT("_read(fd %d, buf %x, nbyte %d)\n", _fd, _buf, _nbyte);
  31
  32    /* null read */
  33    if(_nbyte == 0)
  34       return 0;
  35
  36    hfile = (HANDLE)_get_osfhandle(_fd);
  37    istext = __fileno_getmode(_fd) & O_TEXT;
  38
  39    /* read data */
  40    if (!ReadFile(hfile, bufp, nbyte, &_rbyte, NULL))
  41    {
  42       /* failure */
  43       error = GetLastError();
  44       if (error == ERROR_BROKEN_PIPE)
  45       {
  46          return 0;
  47       }
  48       _dosmaperr(error);
  49       return -1;
  50    }
  51
  52    /* text mode */
  53    if (_rbyte && istext)
  54    {
  55       int found_cr = 0;
  56       int cr = 0;
  57       DWORD count = _rbyte;
  58
  59       /* repeat for all bytes in the buffer */
  60       for(; count; bufp++, count--)
  61       {
  62 #if 1
  63           /* carriage return */
  64           if (*bufp == '\r') {
  65             found_cr = 1;
  66             if (cr != 0) {
  67                 *(bufp - cr) = *bufp;
  68             }
  69             continue;
  70           }
  71           if (found_cr) {
  72             found_cr = 0;
  73             if (*bufp == '\n') {
  74               cr++;
  75               *(bufp - cr) = *bufp;
  76             } else {
  77             }
  78           } else if (cr != 0) {
  79             *(bufp - cr) = *bufp;
  80           }
  81 #else
  82          /* carriage return */
  83           if (*bufp == '\r') {
  84             cr++;
  85           }
  86          /* shift characters back, to ignore carriage returns */
  87           else if (cr != 0) {
  88             *(bufp - cr) = *bufp;
  89           }
  90 #endif
  91       }
  92       if (found_cr) {
  93         cr++;
  94       }
  95       /* ignore the carriage returns */
  96       _rbyte -= cr;
  97    }
  98    DPRINT("%d\n", _rbyte);
  99    return _rbyte;
 100 }