read a Unix binary file

[Arnaud Boëlle]

Hi,

I need to read unix binary files with Excel VBA.

The problem is not to read a binary file. I use :

Dim buffer(1 to 1000) as single
Open file For Binary As 1
Get #1, 1, buffer

The problem is that IEEE binary information are stored left-to-right in UNIX
and right-to-left in WINDOWS
(or the contrary).

I found a first solution to this problem which is

read binary data in a buffer of byte
invert 4 by 4 the bytes of buffer
write buffer in a new binary file
read binary data

Does anyone know a better solution ?

thanks,

Arnaud

[sali]

"Arnaud Boëlle" <boelle.arnaud@neuf.fr> wrote in message
news:d3tu60$dop$1@aphrodite.grec.isp.9tel.net...
> Hi,
>
> I need to read unix binary files with Excel VBA.
>
> The problem is not to read a binary file. I use :
>
> Dim buffer(1 to 1000) as single
> Open file For Binary As 1
> Get #1, 1, buffer
>
> The problem is that IEEE binary information are stored left-to-right in
UNIX
> and right-to-left in WINDOWS
> (or the contrary).
>
> I found a first solution to this problem which is
>
> read binary data in a buffer of byte
> invert 4 by 4 the bytes of buffer
> write buffer in a new binary file
> read binary data
>
> Does anyone know a better solution ?
>

i usualy do a in_memory_swap.

if i need to read long_int, read for bytes from file,
than, in reverse order create character (hex) representation
and let clng() function make number, or
simply multiplying read bytes like:
byte1*256^3+byte2*256^2+byte3*256+byte4

[Arnaud]

"sali" <gabor.salai@tel.net.ba> a écrit dans le message de news:
exMJWI7QFHA.3188@TK2MSFTNGP10.phx.gbl...
> "Arnaud Boëlle" <boelle.arnaud@neuf.fr> wrote in message
> news:d3tu60$dop$1@aphrodite.grec.isp.9tel.net...
>> Hi,
>>
>> I need to read unix binary files with Excel VBA.
>>
>> The problem is not to read a binary file. I use :
>>
>> Dim buffer(1 to 1000) as single
>> Open file For Binary As 1
>> Get #1, 1, buffer
>>
>> The problem is that IEEE binary information are stored left-to-right in
> UNIX
>> and right-to-left in WINDOWS
>> (or the contrary).
>>
>> I found a first solution to this problem which is
>>
>> read binary data in a buffer of byte
>> invert 4 by 4 the bytes of buffer
>> write buffer in a new binary file
>> read binary data
>>
>> Does anyone know a better solution ?
>>
>
> i usualy do a in_memory_swap.
>
> if i need to read long_int, read for bytes from file,
> than, in reverse order create character (hex) representation
> and let clng() function make number, or
> simply multiplying read bytes like:
> byte1*256^3+byte2*256^2+byte3*256+byte4
>


I understand the second solution you propose :
byte1*256^3+byte2*256^2+byte3*256+byte4.
How to do the same for Single ?

I don't understand the first one. How to make a character (hex)
representation ?
I've tried :

dim buffer (1 to 4) as byte
dim x as single
get #1,,buffer
x=csng(buffer) <-------- refused by the compiler !

Thank you for your help,

[sali]

"Arnaud" <boelle.arnaud@neuf.fr> wrote in message
news:d41a03$t8a$1@aphrodite.grec.isp.9tel.net...
>
> "sali" <gabor.salai@tel.net.ba> a écrit dans le message de news:
> exMJWI7QFHA.3188@TK2MSFTNGP10.phx.gbl...
> > "Arnaud Boëlle" <boelle.arnaud@neuf.fr> wrote in message
> > news:d3tu60$dop$1@aphrodite.grec.isp.9tel.net...
> >> Hi,
> >>
> >> I need to read unix binary files with Excel VBA.
> >>
> >> The problem is not to read a binary file. I use :
> >>
> >> Dim buffer(1 to 1000) as single
> >> Open file For Binary As 1
> >> Get #1, 1, buffer
> >>
> >> The problem is that IEEE binary information are stored left-to-right in
> > UNIX
> >> and right-to-left in WINDOWS
> >> (or the contrary).
> >>
> >> I found a first solution to this problem which is
> >>
> >> read binary data in a buffer of byte
> >> invert 4 by 4 the bytes of buffer
> >> write buffer in a new binary file
> >> read binary data
> >>
> >> Does anyone know a better solution ?
> >>
> >
> > i usualy do a in_memory_swap.
> >
> > if i need to read long_int, read for bytes from file,
> > than, in reverse order create character (hex) representation
> > and let clng() function make number, or
> > simply multiplying read bytes like:
> > byte1*256^3+byte2*256^2+byte3*256+byte4
> >
>
>
> I understand the second solution you propose :
> byte1*256^3+byte2*256^2+byte3*256+byte4.
> How to do the same for Single ?
>
> I don't understand the first one. How to make a character (hex)
> representation ?
> I've tried :
>
> dim buffer (1 to 4) as byte
> dim x as single
> get #1,,buffer
> x=csng(buffer) <-------- refused by the compiler !
>
> Thank you for your help,
>

for i=1 to 4
hx$(i)=hex$(byte_array(i))
next
mylng=clng("&H" & hx$(2) & hx$(1) & hx$(4) & hx$(3)) 'just as example of
permutation/reconstruction

floating point number is more complicated than integer.
here is "ieee" reperesentation of 32-bit single float, bit-by-bit.
-------------
S EEEEEEEE FFFFFFFFFFFFFFFFFFFFFFF
0 1 8 9 31

The value V represented by the word may be determined as follows:


V=(-1)**S * 2 ** (E-127) * (1.F) where "1.F" is intended to represent the
binary number created by prefixing F with an implicit leading 1 and a binary
point.
-------------------
original text from:
http://www.psc.edu/general/software/...ieee/ieee.html
[my altavista found near 1million pages dealing with ieee format, this is
just from first of them]

knowing that structure you may recalculate original value, piece-by-piece.
although, i am not sure does hi-lo byte/word swapping apply to float number,
or just integers.