Reading a changing txt file matlab

Question

I have a text file (5 columns "\t" separated) that's being written to by another software. I need to take the readings from the file and do some calculations. Is there a was to read the new lines added to the file and process it then repeat again for every new set of lines. I don't mind a bit of delay as long as it does the job.

My idea is to start reading the file line by line until the end of file, then it will read from where it stopped last until the new end of file ...etc. Can this be done in Matlab? Can I specify the starting line for the file reading? can I also update the end of file point?

To prevent the loop from breaking at the eof point, I think I should set my loop to be controlled by time or anything else, while it should check for eof at the end of every iteration.

I've mostly worked with Matlab, but if there is a better option to use for this purpose (that I can reasonably learn) please feel free to guide me.

Edit1: I've tried using dlmread as you suggested, when I read the file outside the loop it reads the file correctly even when I change R1 and with the other software updating the text. However, when I put it in a loop I get this error: Error using dlmread (line 143) Empty format string is not supported at the end of a file.

Here is my code to read it multiple times:

    clear all
x=0;
R1=0; C1=0;
while(x<10)

    M = dlmread('tst_4.txt','\t',R1,C1);
    R1=length(M);
    x=x+1;
end

Thanks

Answer 1

You can used dlmread(filename,delimiter,R1,C1). Where R1 and C1 are the row and column offset respectively. By setting the row offset to the last row that you have read, you can read the file content excluding what you would have already read.