C PROGRAMMERS ON GNU/LINUX HAVE TWO SETS OF INPUT/OUTPUT functions at their disposal. The standard C library provides I/O functions:
fopen, and so on. The Linux kernel itself provides another set of I/O operations that operate at a lower level than the C library functions.
 The C++ standard library provides iostreams with similar functionality. The standard C library is also available in the C++ language.
Because this book is for people who already know the C language, we’ll assume that you have encountered and know how to use the C library I/O functions.
Often there are good reasons to use Linux’s ...