writing to csv-File - two problems :(

[Carl Schreiber]

Hi,

writing to files has definitely some room for improvement :(
very unconvenient that the Array() only writes bin-files not to csv.

So to do further research in excel I have to glue everything to one string to write this liine at once to the csv.

But now I would like to exchange all (us-) decimal dot by the (german) decimal comma in that line - no way, correct?

That means I have to adapt every single column with numbers individually to get it in Excel.

Very nasty.

Second problem: a new csv-File should have a headline with the names of the columns.

To determin, wether that file is new I do:

      if ( res <= 0 ) handle=FileOpen("neg.csv",FILE_CSV|FILE_WRITE,';');
      else            handle=FileOpen("pos.csv",FILE_CSV|FILE_WRITE,';'); 
      if (handle<=0) {
         Alert("uups, cant open File: ",ErrorDescription(GetLastError()));
         return(false);
      }
      int sz = FileSize( handle );

But this is allways 0 :( FileSize is not working on with handles opend to write - correct?

Do I have to open that file reading first to get the size?

If FileSize does not work on FILE_WRITE, probaly FileTell won't work too on Files opend to write?

Does anybody knows a good workin example to write quite a lot data to a csv-File?

Thanks in advance,

Carl

[Ray]

If you open a file to FILE_WRITE, and haven't written to it yet, the size is always 0.

Read the FileOpen() document carefully.

[Carl Schreiber]

phy:

If you open a file to FILE_WRITE, and haven't written to it yet, the size is always 0.

Read the FileOpen() document carefully.

Absolutely! But it exists and it has three lines and acc.to the folder a size of 2k.

So how do I get to know wether

1) I have to write the headline (size == 0) or not and

2) just add the next two lines?

Neither FileSize() nor FileSeek() and FileTell() seem to give me that information!

Carl

[Ray]

You didn't read carefully.

If you open a file for writing ONLY it creates a new empty file.

To append an existing file you open it ro read AND write.

[Carl Schreiber]

phy:

You didn't read carefully.

If you open a file for writing ONLY it creates a new empty file.

To append an existing file you open it ro read AND write.

ok I read:"If there is a need to add data to an existing file, it must be opened using combination of FILE_READ | FILE_WRITE."

But as most of the times the explanation are written by the produceres and not clear for users.

What the hell means "If FILE_WRITE does not combine with FILE_READ, .."

When and why WRITE & READ do not combine? ("..zero-lenght file" is of course clear to me!)

And this "If FILE_READ does not combine with FILE_WRITE, the file will be opened only if it already exists.

If the file does not exist, it can be created using the FILE_WRITE mode."
Now tell me how can I determin within my program when I do have to write a head-line (=> new file size 0) and when don't?

Carl

[Ray]

This is standard stuff, only slightly flavored by MQL.

http://mycplus.com/tutorials/c-programming-tutorials/file-handling/

[[Deleted]]

phy, i know is google etc. but... such mass of sites out there. u have in a way applied the 'phy' filter and so links u show here always relevant and interesting resources.

maybe u would publish such links/bm's... i for one would prob never get any more work done but such interest is there in ur links.

how bout it?

Best