mmap alt?

[Garey Smiley <ga...@main.slink.com>]

Does any other platform besides OS/2 support the following function? It might
be used instead of mmap() for a faster scoreboard.

  Prototype: 

  FILE *_mfopen (char *buf, const char *mode, size_t size, int inc); 
  
  Description: 

  Open a memory file.  All output to a memory file goes to a buffer in memory.
 The stream returned by _mfopen()  can be used with fprintf(), fputc(),
ftell() and fwrite().  If buf is non-NULL, output goes to the array of size
bytes pointed to by buf.  inc must be zero.  If buf is NULL, output goes to a
buffer allocated with malloc() and resized with realloc().  The initial size
of the buffer is size bytes (which can be zero).  inc must be non-zero.  If
inc is positive, the buffer size is increased by inc bytes whenever it is
full.  If inc is -2, the buffer size is doubled whenever the buffer is full. 
If size is 0 and inc is -2, the initial buffer size is 512 bytes, the buffer
will be allocated on the first output to the stream.  Currently, mode must
point to "wb".  On error, _mfopen() returns NULL.  Do not use fclose() on a
stream created by _mfopen(), use _mfclose() instead.  Do not read from a
stream created by _mfopen(). 

  Return value: 

  _mfopen() returns a new stream.  On error, _mfopen() returns NULL. 

  Restrictions: 

  _fsetmode() doesn't work, newline characters written to the stream are not
expanded to CR/LF. 

  See also: fopen(), _mfclose(), sprintf() 

  Example: See /emx/test/mftest.c 



Garey Smiley
SoftLink Services
garey@slink.com
http://www.slink.com/
(216)848-1312 FAX/Data(216)699-4474

Re: mmap alt?

[Cliff Skolnick <cl...@organic.com>]

Some systems have a tmpfs (memory filesystem, or ramdisk) and do not have 
mmap(), if that is the case, open a file on the ram disk/memory filesystem.

Cliff

On Thu, 8 Feb 1996, Garey Smiley wrote:

> Does any other platform besides OS/2 support the following function? It might
> be used instead of mmap() for a faster scoreboard.
> 
>   Prototype: 
> 
>   FILE *_mfopen (char *buf, const char *mode, size_t size, int inc); 
>   
>   Description: 
> 
>   Open a memory file.  All output to a memory file goes to a buffer in memory.
>  The stream returned by _mfopen()  can be used with fprintf(), fputc(),
> ftell() and fwrite().  If buf is non-NULL, output goes to the array of size
> bytes pointed to by buf.  inc must be zero.  If buf is NULL, output goes to a
> buffer allocated with malloc() and resized with realloc().  The initial size
> of the buffer is size bytes (which can be zero).  inc must be non-zero.  If
> inc is positive, the buffer size is increased by inc bytes whenever it is
> full.  If inc is -2, the buffer size is doubled whenever the buffer is full. 
> If size is 0 and inc is -2, the initial buffer size is 512 bytes, the buffer
> will be allocated on the first output to the stream.  Currently, mode must
> point to "wb".  On error, _mfopen() returns NULL.  Do not use fclose() on a
> stream created by _mfopen(), use _mfclose() instead.  Do not read from a
> stream created by _mfopen(). 
> 
>   Return value: 
> 
>   _mfopen() returns a new stream.  On error, _mfopen() returns NULL. 
> 
>   Restrictions: 
> 
>   _fsetmode() doesn't work, newline characters written to the stream are not
> expanded to CR/LF. 
> 
>   See also: fopen(), _mfclose(), sprintf() 
> 
>   Example: See /emx/test/mftest.c 
> 
> 
> 
> Garey Smiley
> SoftLink Services
> garey@slink.com
> http://www.slink.com/
> (216)848-1312 FAX/Data(216)699-4474
> 
> 

--
Cliff Skolnick                                      cliff@organic.com

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety." -- Benjamin Franklin, 1759