Append a chunk of data on a given position in a txt file

[El_Tipo]

Hello guys,

Iam writing a function that will log data in the flavor of the following image. To later on analyze it with DIAdem.

Iam having trouble inserting the middle part because it overrides part of the buttom section.

I have tried two (2) different ways.

1. I write headings and body and before closing the ref I write the subheadings (middle part) where there is only one space between both "***End of Line***" delimiter expecting to write in between delimiters.

2. Leaving the space that it would take for the subheadings between "***End of Line***" delimiters.

both variants failed, it doesnt move down the last delimiter, instead it overwrites it.

any help in this will be apreaciated.

regards,

[Sam_Sharp]

Unless the file sizes are going to get really large I would split the entire file to find your 'before' and 'after' point (e.g. into the different sections), use concatenate strings to add your new data to the relevant section and then write the whole lot back out to the file.

A slightly more optimised version would find the file position start of the section after the one you're writing to - read all of that into memory, write your data to that file position (until the end of the file) and then append the remainder from memory.

The file IO functions don't have an 'insert' option and instead will overwrite the bytes of the file.

[Brzhou123]

So in this way, if i want append some message to a txt file, i need to read out the txt, and append, then write to the txt, right ?

If write directly, the whole txt will be overwritten ?

Thanks.

[Kevin_Price]

Not exactly.  You can *append* to the end of text file without reading and rewriting the original contents.  (Open it, seek to the end, write the data you want to append, close it.)

This thread addresses the fact that you can't *insert* data between parts of an existing text file.  To accomplish an insert, you *would* need to read and rewrite the existing contents.

-Kevin P

[crossrulz]

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@Brzhou123 wrote:

So in this way, if i want append some message to a txt file, i need to read out the txt, and append, then write to the txt, right ?

If write directly, the whole txt will be overwritten ?

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If you are just adding to the end of the text file, you just need to set the file pointer to be the end of the file before you start writing.  You do this by using the Set File Position function (in the File I/O->Advanced palette), setting the "From" to "End" (defaults to "Front"), and leaving the "Offset" input unwired (defaults to 0).