Find BOMs

Meta Chuh

i am bom, i am bom ;-)

Brigham Narins

Thanks @Meta-Chuh. And thanks @Alan-Kilborn. I really appreciate your interest in this.

i only found some ps, batch, python scripts that list all bom files externally, but you have probably seen them as well (stackoverflow)

I did see those, yes. Ideally I’d like to come up with a solution inside Notepad++, because these outside scripts and such seem to call for expertise and programs I don’t have.

ps: if you are faster in implementing something like this, please share it.
it would be an enrichment.

I’ll do my best and keep you posted, but I came to you for enrichment and enlightenment! :)

Alan Kilborn

@Brigham-Narins said:

I’d like to come up with a solution inside Notepad++

I understand why you’d want this. My earlier comment was intended to mean that I believe the BOM stuff is “consumed” when a file is opened, and thus isn’t “obtainable” later. I haven’t done any investigation, so could be totally wrong about this…

By “inside Notepad++”, I’m sure you could write a Pythonscript that could open files in binary and detect BOM. That may or may not qualify as “inside Notepad++” and of course might be more effort than you were hoping to put in…

Alan Kilborn

I’m waiting for a Python program to do its work, so I started playing. Here’s a Pythonscript that does what I mentioned, operating on all files currently open within Notepad++. It seemed to work for the little bit of testing I did with it.

for (filename, bufferID, index, view) in notepad.getFiles():
    inf = open(filename, 'rb')
    data_at_start_of_file = inf.read(3)
    inf.close()
    if len(data_at_start_of_file) >= 3 and ord(data_at_start_of_file[0]) == 0xEF and ord(data_at_start_of_file[1]) == 0xBB and ord(data_at_start_of_file[2]) == 0xBF:
        print(filename, ': found utf-8 bom')
    elif len(data_at_start_of_file) >= 2 and ord(data_at_start_of_file[0]) == 0xFE and ord(data_at_start_of_file[1]) == 0xFF:
        print(filename, ': found ucs-2 big endian bom')
    elif len(data_at_start_of_file) >= 2 and ord(data_at_start_of_file[0]) == 0xFF and ord(data_at_start_of_file[1]) == 0xFE:
        print(filename, ': found ucs-2 little endian bom')

guy038

Hello, @brigham_narins, @meta-chuh, @alan-kilborn and All,

To simply answer your question, I would say that, among all files created from within N++, the files having a BOM ( a Byte Order Mark ) are :

The files with UTF8-BOM encoding, which have a 3 bytes invisible BOM ( EF BB BF )
The files with UCS-2 BE BOM encoding, which have a 2 bytes invisible BOM ( FE FF )
The files with UCS-2 LE BOM encoding, which have a 2 bytes invisible BOM ( FF FE )

In all the other encodings, BOM does not exist !

Here is an other way to verify the presence of a BOM :

Click on the View > Summary... menu option
Calculate the difference File length (in byte) - Current document length !

You’ve just got the BOM length, which should be 2 or 3 bytes, depending on the file encoding

Best Regards,

guy038

PeterJones

@Alan-Kilborn said:

Here’s a Pythonscript that does what I mentioned, operating on all files currently open within Notepad++.

Thanks for that framework. My thought process was that I wanted to see whether the scintilla buffer contained the BOM or whether it was filtered out before then. With this framework, I added some scintilla-buffer editor.xxx commands, and found that no, the BOM is not in the scintilla buffer:

firstBufferID = notepad.getCurrentBufferID()
for (filename, bufferID, index, view) in notepad.getFiles():
    inf = open(filename, 'rb')
    data_at_start_of_file = inf.read(3)
    inf.close()
    if len(data_at_start_of_file) >= 3 and ord(data_at_start_of_file[0]) == 0xEF and ord(data_at_start_of_file[1]) == 0xBB and ord(data_at_start_of_file[2]) == 0xBF:
        console.write(filename+': found utf-8 bom'+'\n')
    elif len(data_at_start_of_file) >= 2 and ord(data_at_start_of_file[0]) == 0xFE and ord(data_at_start_of_file[1]) == 0xFF:
        console.write(filename+': found ucs-2 big endian bom'+'\n')
    elif len(data_at_start_of_file) >= 2 and ord(data_at_start_of_file[0]) == 0xFF and ord(data_at_start_of_file[1]) == 0xFE:
        console.write(filename+': found ucs-2 little endian bom'+'\n')

    # addendum:
    notepad.activateBufferID( bufferID )
    str = editor.getText()
    console.write('buffer: length = {}\n'.format(len(str)))
    for i in range(3):
        console.write('\t#{}: {} => {}\n'.format(i, str[i], ord(str[i])))

notepad.activateBufferID( firstBufferID )

Which results in:

C:\Users\peter.jones\...\Peter's Scratchpad.md: found ucs-2 little endian bom
buffer: length = 10861
    #0: ~ => 126
    #1: ~ => 126
    #2: ~ => 126
C:\usr\local\apps\notepad++\plugins\Config\PythonScript\scripts\NppForumPythonScripts\17244-utf-bom-reader.py: found utf-8 bom
buffer: length = 1513
    #0: # => 35
    #1:   => 32
    #2: e => 101

(And no, normally my scratchpad is in UTF8-BOM, not in UCS-2 LE BOM; I just changed it’s encoding temporarily to test out the other BOM-detections.)

Alan Kilborn

@PeterJones said:

and found that no, the BOM is not in the scintilla buffer

…we’re back to what I postulated in the beginning: meta!

Meta Chuh

@Alan-Kilborn

…we’re back to what I postulated in the beginning: meta!

yes … you were calling ? ;-)

Alan Kilborn

@Meta-Chuh

LOL

Okay, that has me thinking…what does your username actually mean?

Meta Chuh

@Alan-Kilborn

it’s my real name.
unfortunately our family has generations of such strange names.
my brothers for example are called pikachuh and raichuh.

here’s a family picture of us:

Imgur

😄

seriously: i got meta as a nick name ages ago, as when i was little, i started to use anything for everything, beyond of what specific items were originally intended, or designed to be used for … and through the years, more and more of doing that actually started to work out, without anybody (including me) understanding why. 😉