[RESOLVED] Notepad handling memory

[jkepler]

Hi,

Does anyone knows the maximum file size that notepad can handle? I can open a couple of MB. But what's the safe value without getting an error?

Kind regards,

JKepler

[baja_yu]

I think it can open a lot more but it's slow. Wordpad is much faster.

[jkepler]

Hi,

You're entirely right regarding Wordpad speed. Thanks.

Kind regards,

JKepler

[LaVolpe]

FYI. Notepad uses a standard Edit control. This is a pre-defined window class. As such it has pre-defined limits but can be modified. In order to know what the "safe" limit is, one has to query the control to get that limit

Oh, WordPad also uses a pre-defined window class: Rich Edit Control

[Lord Orwell]

Hi,

Does anyone knows the maximum file size that notepad can handle? I can open a couple of MB. But what's the safe value without getting an error?

Kind regards,

JKepler

it was originally limited to 32kilobytes, but that limit no longer exists. There isn't really a limit.

[jkepler]

FYI. Notepad uses a standard Edit control. This is a pre-defined window class. As such it has pre-defined limits but can be modified. In order to know what the "safe" limit is, one has to query the control to get that limit

Oh, WordPad also uses a pre-defined window class: Rich Edit Control

Hi,

Is there a way of making that query in VB6 code? For Notepad, for instance?

Kind regards,

Jkepler

[LaVolpe]

@Lord Orwell
Not arguing... I'd think the limit would be about 4GB theoretically. The EM_SETLIMITTEXT message on 32bit machines is a Long value; thereby making its maximum value ~2^32. But it also may be dependent upon O/S (Win9x vs NT-based). However, MSDN docs specifically indicate you can exceed whatever limit by simply 'pasting' more code at the end of the document. System memory will most likely be in play too.

@jkepler
You'd have to get the hWnd of the NotePad text window, then use SendMessage API to send it a EM_GETLIMITTEXT message.

More Details

The EM_SETLIMITTEXT message limits only the text the user can enter. It does not affect any text already in the edit control when the message is sent, nor does it affect the length of the text copied to the edit control by the WM_SETTEXT message. If an application uses the WM_SETTEXT message to place more text into an edit control than is specified in the EM_SETLIMITTEXT message, the user can edit the entire contents of the edit control.

Before EM_SETLIMITTEXT is called, the default limit for the amount of text a user can enter in an edit control is 32,767 characters.

Edit controls on Windows NT/2000/XP: For single-line edit controls, the text limit is either 0x7FFFFFFE bytes or the value of the wParam parameter, whichever is smaller. For multiline edit controls, this value is either –1 bytes or the value of the wParam parameter, whichever is smaller.

Edit controls on Windows 95/98/Me: For single-line edit controls, the text limit is either 0x7FFE bytes or the value of the wParam parameter, whichever is smaller. For multiline edit controls, this value is either 0xFFFF bytes or the value of the wParam parameter, whichever is smaller.

Looking at the MSDN documentation above, it appears the high bit of the Long value for EM_SETLIMITTEXT may be reserved which could mean the maximum limit may be ~2GB. Also, out of curiosity, I sent a new Notepad instance the message and it returned a value of -1. Though none of the above really means squat. Even if you try to open a 500+ MB file, Notepad will tell you to use another editor. Though I opened an 18MB file with no issues. Even though the Edit control's limitation may exceed the bytes being read, Notepad itself may have set restrictions on file sizes.