Re: Raw file i/o

[Guido Dietz]

You wrote:
>One thing I would like to add is to add an optional third argument to
>fopen() that would set the default conversion type.  The argument
>should be a string, and should be compatible with the way Matlab
>works (this is from the Matlab help and was posted to
>comp.soft-sys.matlab this week):
>
>[FID, MESSAGE] = FOPEN('filename',permission, machineformat) opens the
>        specified file with the specified permission and treats data read
>        using FREAD or data written using FWRITE as having a format given
>        by machineformat. machineformat is one of the following strings:
> 
>        'native'      or 'n' - local machine format - the default
>        'ieee-le'     or 'l' - IEEE floating point with little-endian
>                               byte ordering
>        'ieee-be'     or 'b' - IEEE floating point with big-endian
>                               byte ordering
>        'vaxd'        or 'd' - VAX D floating point and VAX ordering
>        'vaxg'        or 'g' - VAX G floating point and VAX ordering
>        'cray'        or 'c' - Cray floating point with big-endian
>                               byte ordering
>        'ieee-le.l64' or 'a' - IEEE floating point with little-endian
>                               byte ordering and 64 bit long data type
>                               (currently supported on: alpha, sgi, ibm_rs,
>                                hp300, vax, and cray platforms only)
>
>Perhaps the strings you have chosen for the new built-in variables
>should be changed to match these (or at least accept them too).
>
>: After some testings (two or three days) I will send you a patch and
>: hope that you will add it to the next release.
>
>Thanks, I'm looking forward to seeing them.
>
>jwe

I reckon this is a good idea: I am just working on it. The builtin variable 
'raw_io_format' I put in the waste paper basket. 

Therefore the new method:
* Extracting and modifying the int and float conversion routines
  from "src/load-save.cc" to "liboctave/FConc.cc", 
  "liboctave/FConc.h" and "liboctave/FSwap.h". Changes in 
  "liboctave/Makefile.in".
* implementing the conversion routines in "liboctave/dMatrix.cc".
* adding 'file_arch' and others to the file_info structure and modifying
  the 'fopen*' calls as  well as 'fread_internal' and 'fwrite_internal' in
  "src/load-save.cc".

Only for the 'ieee-le.l64' I am to lazy, but I hope you'll respond:

>I wouldn't worry too much about this.  Perhaps someone who has a need
>for these conversions will eventually implement them.

as in the last mail!

Bye bye
G.



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