How to use random read and write the suffix name for ".txt" file data block

First please be specific about what you are using. The C language has both low-level and stream-oriented I/O. I will assume you are using stream I/O.

Programmers in the past often used fixed-length records. Younger programmers choke on the idea. It does get complicated in the C++ language due to classes.

I forget the details of what function is used to read data using C. I could look it up but so can you.

The main problem is that if you read 60 characters then the data will not have the zero byte at the eend of each string. You can use one of the functions in strncpy_s, _strncpy_s_l, wcsncpy_s, _wcsncpy_s_l, _mbsncpy_s, _mbsncpy_s_l to copy each string to another place where you can add a zero byte.

Other than that, can you specify what you need help with? What is it that you do not know how to do?