## 5 Input and Output (`stdio.h`) ¶

This chapter comprises functions to manage files or other input/output streams. Among these functions are subroutines to generate or scan strings according to specifications from a format string.

The underlying facilities for input and output depend on the host system, but these functions provide a uniform interface.

The corresponding declarations are in `stdio.h`.

The reentrant versions of these functions use macros

    _stdin_r(reent)
    _stdout_r(reent)
    _stderr_r(reent)

instead of the globals `stdin`, `stdout`, and `stderr`. The argument reent is a pointer to a reentrancy structure.