How to read line by line from one file and find each line to another file and locate it?

Dear all,

I have 2 .csv files. The first thing i want to do is to read the first file line by line. All these lines are in the second file but in different row. I need to find where in the second file is each of the line (the number of line). Does anyone konw how to solve this problem?

Best regrds, Konstantina

Answer 1

[Guillaume]

A simple way:

leftcontent = strsplit(fileread('c:\somewhere\your\1stfile.csv'), {'\n', '\r'}); %read 1st file and split into lines
rightcontent = strsplit(fileread('c:\somewhere\your\2ndfile.csv'), {'\n', '\r'}); %read 1st file and split into lines
[foundinright, locationinright] = ismember(leftcontent, rightcontent)

locationinright contains the line number where each line of the first file is found in the second file (or 0 if not present), in the order of the lines in the first file.

[Kona]

Dear Guillaume, thank you very much for the answer. I did what you propose and i had this error: Undefined function 'strsplit' for input arguments of type 'cell'. Do you Know what does it mean?

[Kona]

I had two columns!! I concatenated them in one and the problem is solved! Thank you again!!!

[Guillaume]

It means that your version of matlab is older than R2013a (always a good idea to specify your matlab version if it's old), since that's where strsplit was introduced.

You can replace the code with:

findeol = sprintf('(?:%c|%c)+', 13, 10);
leftcontent = regexp(fileread('c:\somewhere\your\1stfile.csv'), findeol, 'split'); %read 1st file and split into lines
rightcontent = strsplit(fileread('c:\somewhere\your\2ndfile.csv'), findeol, 'split'); %read 1st file and split into lines
[foundinright, locationinright] = ismember(leftcontent, rightcontent)

which should work in versions < R2013a.

By the way don't accept an answer if it does not work for you.