Read from files that have a file pointer to a buffer stream within C to able to access. Can also write/append back to disk.
Some functions for reading that can be used are fgets, fgetc, feof and fread.
Modes to read for normal txt files = r, r+, w+ and a+. If the file is a binary file (.bin), use rb, rb+, wb+ and ab+
Have to open a file to be able to read etc. When changing modes, need to close then reopen. Remember to close the file pointer after use.
#include <stdio.h>
void main(){
FILE *pointername;
pointername = fopen("name and possibly path if required with mount point", "mode");
Read etc.
fclose(pointername);
}