Stdio.h

stdio.h, which stands for "standard input/output header", is the header in the C standard library that contains macro definitions, constants, and declarations of functions and types used for various standard input and output operations. The functionality descends from a "portable I/O package" written by Mike Lesk at Bell Labs in the early 1970s. [cite book|last=Kernighan|first=Brian|authorlink=Brian Kernighan|coauthors=Rob Pike|title=The UNIX Programming Environment|publisher=Prentice Hall|location=Englewood Cliffs|date=1984|pages=pg. 200] C++, for compatibility reasons, includes stdio.h as well as an essentially equivalent header, cstdio.

Functions declared in stdio.h are extremely popular, since as a part of the C standard library, they are guaranteed to work on any platform that supports C. Applications on a particular platform might, however, have reasons to use the platform's I/O routines, rather than the stdio.h routines.

Example usage

All functions in C (and its many derivatives) are declared in header files. Thus, programmers have to include the stdio.h header in the source code in order to use the functions declared in it.

#include int main(void){ int ch; while ((ch = getchar()) != EOF) putchar(ch); putchar(' '); return 0;}

The above program reads all input from standard input and echoes it to standard output, byte by byte, adding a newline at the end of its output.

Member functions

Functions declared in stdio.h can generally be divided into two categories: the functions for file manipulation and the functions for input-output manipulation.

Member types

Data types defined in the stdio.h header include:
* FILE - a structure containing the information about a file or text stream needed to perform input or output operations on it, including:
** a file descriptor
** the current stream position
** an end-of-file indicator
** an error indicator
** a pointer to the stream's buffer, if applicable
* fpos_t - a non-array type capable of uniquely identifying the position of every byte in a file.
* size_t - an unsigned integer type which is the type of the result of the sizeof operator.

ee also

*Large file support

References