stdio.h

This header file contains two type declarations. Refer the following table.

Table 1. Type Definitions in stdio.h
Type Definition	Description
`FILE`	Defines a type for a file descriptor.
`fpos_t`	A type to hold the position in the file as needed by fgetpos() and fsetpos().

The following table lists the constants defined in stdio.h.

Table 2. Constants Defined in stdio.h
Constant	Description
`BUFSIZ`	Buffer size for setbuf().
`EOF`	Negative constant to indicate end-of-file.
`FILENAME_MAX`	Maximum length of a filename.
`FOPEN_MAX`	Maximum number of open files.
`_IOFBF`	To set full buffering in setvbuf().
`_IOLBF`	To set line buffering in setvbuf().
`_IONBF`	To switch off buffering in setvbuf().
`SEEK_CUR`	fseek() positions relative from current position.
`SEEK_END`	fseek() positions from the end of the file.S
`SEEK_SET`	fseek() positions from the start of the file.
`TMP_MAX`	Maximum number of unique filenames tmpnam() can generate.

There are three variables for the standard I/O streams:

  extern FILE *  stderr,   *stdin,   *stdout;