Serial communication

I want to read sixty characters at a time from the SD card and store it in the buffer(in an array of size 60) after which i want to manipulate the received data. After manipulation i want to read the next set of 60 characters from the SD card (start reading from where i left reading) and continue the process. How do i do that… The major problem is reading the data from where i left reading earlier…
The following is a piece of my code

read_SD.ino (2.12 KB)

Every sequential file read function that I've ever seen, does exactly what you need with no modifications.

Please post your code here to make it easier to deal with rather than having to download it.

Don't keep opening (and not closing) the file each time. Once i has been incremented above 30, nothing happens. It seems like it might be useful at some point to set it back to 0.

You can read all 30 (or 60) characters in one call to read().

By the way, the program, and your question, appear to have NOTHING to do with serial communication.