data to text file with header

[Schwede]

Hello,

for my test application i want to store the test data into a text file with header. This should be like this:

name, serial, count, min. current, max. current

Mister Smith

1234567890

111

10

1000

data:

1 345 34

2 355 23

3 360 34

...

The first row are only informations about the headers rows. "data:" is the start marker of the data. The data consists  of a number, the mean value of current an the test time in s.

Now i write an string array to the text file, but if the length of the header change i overwrite the data. For example the name is Mister John Smith.

In my program i can create a new file with header and i can change the header later. In the measurement routine i put the data into the file.

How can I solve this?

thankyou

schwede

[GerdW]

Hi Schwede,

the easiest would be to disallow changing the header after start of the measurement. (That's reasonable, don't you think so?)

The next best option is to use a fixed-sized header - easiest when you need to change the header later on.

A 3rd option is to reload the whole file, change the header and write the whole file again - there is no "insertion" possible for files...

[Schwede]

Hello,

"The next best option is to use a fixed-sized header - easiest when you need to change the header later on."

How can I do this?

[GerdW]

Hi Schwede,

by writing a fixed-sized string? (fill up with spaces, empty lines, tabs, #, whatever you like )

[Schwede]

I think the constant Header size is good, but i can`t made it.

Have you an example for me please?

[GerdW · Accepted solution]

Hallo Schwede,

here's an example:

Be carefule and make some checks, at the moment it will cut "your input" when it exceeds 512 bytes...