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how to inspect the bytes in a file?

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# 1  
Old 04-13-2009
how to inspect the bytes in a file?
What is the easiest way to inspect the bytes stored in a file?

Ideally, If my file was 10 bytes each of which had only the high bit set, I'd be able to browse for it and get output like this:
Code:
01 - 10000000
02 - 10000000
03 - 10000000
04 - 10000000
05 - 10000000
06 - 10000000
07 - 10000000
08 - 10000000
09 - 10000000
10 - 10000000

or perhaps this:
Code:
01 - 80
02 - 80
03 - 80
04 - 80
05 - 80
06 - 80
07 - 80
08 - 80
09 - 80
10 - 80

I'm currently coding on a Mac.
# 2  
Old 04-14-2009
In pseudo-code?
Code:
open file
while !eof
    read byte
    if matching
        print counter - byte
    counter++
close file

# 3  
Old 04-14-2009
That I already knew. Translating that pseudo-code into actual C or C++ or Java code is hardly the easiest way to do this. Someone recommended googling 'Hex Editor' which I will be doing now.
# 4  
Old 04-14-2009
Since your original posting sounded (and still does) like "Please do my homework for me" I didn't want to spill too much. So please tell me: are you learning C/C++/Java? By yourself or in class? Is this a homework assignment? What have you got so far? Are you stuck on any specific part?
I'll be happy to help someone learn as long as I'm sure I'm not helping cheat.
# 5  
Old 04-14-2009
I graduated from college years ago. I have since been writing a lot of PHP and have rarely, if ever, dealt with raw binary files. I can totally appreciate your desire to not assist those little cheats. I am not one of them. I am, however, returning to C++ after many years absence.

I'm using hexdump which seems perfect:
Code:
My-Mac:red sneakyimp$ hexdump -vx rgb.raw
0000000    0000    0000    0000    0000    0000    0000    0000    0000
0000010    0000    0000    0000    0000    ffff    0000    0000    0000
0000020    0000    0000
0000024

# 6  
Old 04-14-2009
If you only want to display a raw file, hexdump is perfect for that. From your original post, however, it seemed that you only want to display those postition matching a certain pattern of that file.

Should you want to implement something similar yourself, file opening and loops work pretty much the same as in PHP, "strings" are really arrays of char (which is 1 byte), and printf has a %X conversion, which will output the value as hex. If you need more information, feel free to ask.
# 7  
Old 04-14-2009
I think we got confused since you were asking in the programming forum. You just wanted an existing tool, people thought you wanted us to make you one. Smilie
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