modify data on sd card

hello everyone, am new to sd card module. i want to search a record on a file on the sd card and modify the searched record. i dont know if this is possible. i am saving my data in a .csv file. any link or suggestion will be of help.

You'll need to read in the data. Modify whatever you need to modify. Write the data back.

discussion on reading CSV file

If all the records are the same length, writing over one record is easy.

If the records are different lengths, replacing a long one with a short one, or a short one with a long one, is a bit more challenging. In this case, you’d need to read the data from one file, writing to another, until you get to the record that needs to be replaced. You’d read, and discard, that record from the first file, and then write the correct record to the second file. Then, you’d read the rest of the first file and write it to the second file.

When done, close both files, delete the first one, and rename the second one.