FILENO(3)

NAME
4.15 `fileno'--return file descriptor associated with stream

SYNOPSIS
     #include <stdio.h>
     int fileno(FILE *FP);

DESCRIPTION
You can use `fileno' to return the file descriptor identified by FP.

RETURNS
`fileno' returns a non-negative integer when successful. If FP is not an open stream, `fileno' returns -1.

PORTABILITY
`fileno' is not part of ANSI C. POSIX requires `fileno'.
   Supporting OS subroutines required: none.

SEE ALSO
fileno is part of the library. The full documentation for is maintained as a Texinfo manual. If info and are properly installed at your site, the command

    info

will give you access to the complete manual.