GPGME callback function problem

[Werner Koch]

On Tue, 11 Sep 2007 02:24, hira at atlas-is.co.jp said:

> I failed using _write(),(infinit loop?) so I replace it to _gpgme_io_write().
> I think the reason is _gpgme_io_write() can handle CriticalSection in sema.h.

You may not use any function prefixed with "_gpgme"!  These are internal
functions and may change without notice.

Under Windows you need to use WriteFile and ReadFile and not write (or
_write which is identical to write).  Marcus already mentioned this.

Translation between the libc and system handles can be done with code
like this:

  /* This function is a NOP for POSIX systems but required under Windows
     as the file handles as returned by OS calls (like CreateFile) are
     different from the libc file descriptors (like open). This function
     translates system file handles to libc file handles.  FOR_WRITE
     gives the direction of the handle.  */
  int
  translate_sys2libc_fd (gnupg_fd_t fd, int for_write)
  {
  #ifdef HAVE_W32_SYSTEM
    int x;
  
    if (fd == GNUPG_INVALID_FD)
      return -1;
    
    /* Note that _open_osfhandle is currently defined to take and return
       a long.  */
    x = _open_osfhandle ((long)fd, for_write ? 1 : 0);
    if (x == -1)
      log_error ("failed to translate osfhandle %p\n", (void *) fd);
    return x;
  #else /*!HAVE_W32_SYSTEM */
    return fd;
  #endif
  }
  
  
If you are interested in the Windows API design, you should get Johnson
M. Hart's "Windows System Programming".  Actually this book a must have
for all Unix hackers who need to work for Windows.



Salam-Shalom,

   Werner


-- 
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