read.c

德州仪器(TI) 的超低功耗16 位RISC 混合信号处理器的MSP430 平台为电池供电的测量应用提供了最终解决方案。应用包括便携式医疗设备、低功耗工业操作、无线、实用计量等

/*******************
 *
 * Copyright 1998-2003 IAR Systems.  All rights reserved.
 *
 * $Revision: 1.13 $
 *
 * This is a template implementation of the "__read" function used by
 * the standard library.  Replace it with a system-specific
 * implementation.
 *
 * The "__read" function reads a number of bytes, at most "size" into
 * the memory area pointed to by "buffer".  It returns the number of
 * bytes read, 0 at the end of the file, or _LLIO_ERROR if failure
 * occurs.
 *
 * The template implementation below assumes that the application
 * provides the function "MyLowLevelGetchar".  It should return a
 * character value, or -1 on failure.
 *
 ********************/

#include <yfuns.h>

_STD_BEGIN

#pragma module_name = "?__read"

int MyLowLevelGetchar();

size_t __read(int handle, unsigned char * buffer, size_t size)
{
  /* Remove the #if #endif pair to enable the implementation */
#if 0    

  int nChars = 0;

  /* This template only reads from "standard in", for all other file
   * handles it returns failure. */
  if (handle != _LLIO_STDIN)
  {
    return _LLIO_ERROR;
  }

  for (/* Empty */; size > 0; --size)
  {
    int c = MyLowLevelGetchar();
    if (c < 0)
      break;

    *buffer++ = c;
    ++nChars;
  }

  return nChars;

#else

  /* Always return error code when implementation is disabled. */
  return _LLIO_ERROR;

#endif
}

_STD_END