Re: [ros-kernel] New proposed fix: for getchar

[KJK::Hyperion <no...@li...>]

At 10.16 03/05/2002, you wrote:
[...]
>BUT _read (in msvcrt\io\read.c) doesn't want to return until it's read the 
>size requested (filebuf asks for 4096), even if enter is pressed
[...]

proposed patch for read.c (fixed logical flaw, general cleanup, added some 
comments. Some perplexities about the handling of carriage returns in text 
files):

Index: io/read.c
===================================================================
RCS file: /CVS/ReactOS/reactos/lib/msvcrt/io/read.c,v
retrieving revision 1.4
diff -u -r1.4 read.c
--- io/read.c   1 Apr 2002 21:50:56 -0000       1.4
+++ io/read.c   3 May 2002 20:03:46 -0000
@@ -16,38 +16,49 @@

  size_t _read(int _fd, void *_buf, size_t _nbyte)
  {
-   DWORD _rbyte = 0, nbyte = _nbyte, count;
-   int cr;
+   DWORD _rbyte = 0, nbyte = _nbyte;
     char *bufp = (char*)_buf;
+   HANDLE hfile;
+   int istext;

     DPRINT("_read(fd %d, buf %x, nbyte %d)\n", _fd, _buf, _nbyte);

-   while (nbyte)
+   /* null read */
+   if(_nbyte == 0)
+      return 0;
+
+   hfile = _get_osfhandle(_fd);
+   istext = __fileno_getmode(_fd) & O_TEXT;
+
+   /* read data */
+   if (!ReadFile(hfile, bufp, nbyte, &_rbyte, NULL))
     {
-      if (!ReadFile(_get_osfhandle(_fd), bufp, nbyte, &_rbyte, NULL))
-      {
-         return -1;
-      }
-      if (_rbyte == 0)
-         break;
-      if (__fileno_getmode(_fd) & O_TEXT)
+      /* failure */
+      return -1;
+   }
+
+   /* text mode */
+   if (_rbyte && istext)
+   {
+      int cr = 0;
+      DWORD count = _rbyte;
+
+      /* repeat for all bytes in the buffer */
+      for(; count; bufp++, count--)
        {
-        cr = 0;
-        count = _rbyte;
-         while (count)
-        {
-            if (*bufp == '\r')
-              cr++;
-           else if (cr != 0)
-                  *(bufp - cr) = *bufp;
-            bufp++;
-           count--;
-        }
-        _rbyte -= cr;
-         bufp -= cr;
+         /* carriage return */
+         if (*bufp == '\r')
+            cr++;
+         /* shift characters back, to ignore carriage returns */
+         else if (cr != 0)
+            *(bufp - cr) = *bufp;
+
        }
-      nbyte -= _rbyte;
+
+      /* ignore the carriage returns */
+      _rbyte -= cr;
     }
-   DPRINT("%d\n", _nbyte - nbyte);
-   return _nbyte - nbyte;
+
+   DPRINT("%d\n", _rbyte);
+   return _rbyte;
  }