NAME

fileno − Maps a stream pointer to a file descriptor

LIBRARY

Standard C Library (libc.so, libc.a)

SYNOPSIS

#include <stdio.h>

int fileno(
        FILE ∗stream);

STANDARDS

Interfaces documented on this reference page conform to industry standards as follows:

fileno():  XPG4, XPG4−UNIX

Refer to the standards(5) reference page for more information about industry standards and associated tags. 

PARAMETERS

streamSpecifies the input stream. 

DESCRIPTION

The fileno() function returns the integer file descriptor associated with the stream pointed to by stream. 

NOTES

[Digital]  The fileno() function may be a macro (depending on the compile-time definitions used in the source).  Consequently, you cannot use this interface where a function is necessary; for example, a subroutine pointer cannot point to the interface. 

RETURN VALUES

Upon successful completion, the fileno() macro returns the integer value of the file descriptor associated with the stream parameter.  Otherwise, the value -1 is returned. 

RELATED INFORMATION

Functions: clearerr(3), fdopen(3), feof(3), ferror(3), fopen(3), open(2)

Standards: standards(5)