Clear txt file

[john7]

Hi All !

I write some data to a file, but before i do it i want to clear the file from previous content.

Surprisingly i didn't find any control/function to do the operation.

I'm using LV 7.1.

[GerdW · Accepted solution]

Hi John,

ever tried to "create or replace" a file instead of "open or create"?

There also exists a "Delete File" function, in case you don't trust the file open function and their options...

[Ken_Naylor]

Since you have the Path to the file you want to replace in the 'WRITE' case you coud use the 'Delete.vi. in 'Advance File Functions' Bottom right in the FILE I/O section of the Programming pallette.

[john7]

Create or replace option pops-up a dialog. Delete is an option, also in C/C#  it's quite a simple operation to clear a file.

[john7]

It's OK! There is a flag to suppress pop-up dialog. Thanks a lot!

[GerdW]

Hi John,

"Delete is an option, also in C/C#  it's quite a simple operation to clear a file."

Either use the Delete function or try the SetFileSize/SetFilePosition functions...

How would you do that in C/C++/C# anyway?

[john7]

"How would you do that in C/C++/C# anyway?"

It's library functions but I think on a low level it goes like this (it's pseudo code):

while(!EOF)

{

   clear(or replase) char at position;

    increment position;

}