topic Re: How do extract parts of a binary file and evaluate them separately? in Discussions

How do extract parts of a binary file and evaluate them separately?

lala — Fri, 09 Jun 2023 17:04:57 GMT

Hello!

For example this file with this script can get the first data is a date.

How do I use a script to extract this "A2 3F 32 01"
and use a script to calculate its corresponding decimal value= 20070306

Thanks!

Re: How do extract parts of a binary file and evaluate them separately?

lala — Thu, 21 Jul 2022 04:30:20 GMT

This will not reverse success

bb = Load Text File( "I:\E\00820070306.zst", blob() );
ymd = Blob To Matrix( bb, "uint", 4, "little", 8 );

a=Munger(char(bb),contains(char(bb),"(")+4,12);
b=Char To blob(a, "utf-8" );;
mat=blobtomatrix(b, "uint", 4, "little", 8 );

Re: How do extract parts of a binary file and evaluate them separately?

jthi — Thu, 21 Jul 2022 05:12:04 GMT

Maybe BLOB Peek(blob, offset, length) would work? Also this might be a good watch

Re: How do extract parts of a binary file and evaluate them separately?

lala — Thu, 21 Jul 2022 05:26:29 GMT

Thanks!

Re: How do extract parts of a binary file and evaluate them separately?

txnelson — Thu, 21 Jul 2022 05:58:49 GMT

Your code

bb = Load Text File( "I:\E\00820070306.zst", blob() );
ymd = Blob To Matrix( bb, "uint", 4, "little", 8 );

is creating a 2 dimensional matrix you are calling "ymd" with the values converted to decimal values. All you have to do, is to create a new data table, then create a new column and set the values in the new column to the first column in the matrix ymd.

Names Default To Here( 1 );

bb = Load Text File( "I:\E\00820070306.zst", blob() );
ymd = Blob To Matrix( bb, "uint", 4, "little", 8 );

dt = New Table( "zst" );
dt << New Column( "col 1" );
	Column( dt, 1 ) << set values( ymd[0, 1] );

Then just repeat it for the remaining 7 columns in the matrix

Re: How do extract parts of a binary file and evaluate them separately?

lala — Thu, 21 Jul 2022 06:30:56 GMT

Thank Jim!

Yes, I got this code from Craige.

This code is useful when it knows the binary data structure.

But this new file I don't know its data structure.I'm on a quest.

I'm wrapping this file at 00 intervals.I get the data for this.

Except for the first line which I know contains the date.

But the data starting in the second line is integer data, floating point data.But which field is a floating point, or an integer.I don't know.

I can only restore the comparison field by field.

I still haven't figured it out yet.

Re: How do extract parts of a binary file and evaluate them separately?

txnelson — Thu, 21 Jul 2022 06:38:47 GMT

Best of luck

Re: How do extract parts of a binary file and evaluate them separately?

lala — Thu, 21 Jul 2022 08:47:58 GMT

How can take something in hexadecimal form and compute it as a floating point?

~D9~40~D9~CE

The following code ran incorrectly

b = Char To Blob( "~D9~40~D9~CE", "ascii~hex" );
f = Blob To Matrix( b, "float", 4, "little", 4 );

Thanks!

Re: How do extract parts of a binary file and evaluate them separately?

lala — Thu, 21 Jul 2022 08:49:06 GMT

OK
I just wrote the wrong code.

Thanks!