|
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | CONFORMING TO | SEE ALSO | COLOPHON |
|
|
|
FILENO(3) Linux Programmer's Manual FILENO(3)
fileno - obtain file descriptor of a stdio stream
#include <stdio.h>
int fileno(FILE *stream);
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
fileno():
_POSIX_C_SOURCE
The function fileno() examines the argument stream and returns
the integer file descriptor used to implement this stream. The
file descriptor is still owned by stream and will be closed when
fclose(3) is called. Duplicate the file descriptor with dup(2)
before passing it to code that might close it.
For the nonlocking counterpart, see unlocked_stdio(3).
On success, fileno() returns the file descriptor associated with
stream. On failure, -1 is returned and errno is set to indicate
the error.
EBADF stream is not associated with a file.
For an explanation of the terms used in this section, see
attributes(7).
┌──────────────────────────────────────┬───────────────┬─────────┐
│Interface │ Attribute │ Value │
├──────────────────────────────────────┼───────────────┼─────────┤
│fileno() │ Thread safety │ MT-Safe │
└──────────────────────────────────────┴───────────────┴─────────┘
The function fileno() conforms to POSIX.1-2001 and POSIX.1-2008.
open(2), fdopen(3), stdio(3), unlocked_stdio(3)
This page is part of release 5.13 of the Linux man-pages project.
A description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
2021-03-22 FILENO(3)
Pages that refer to this page: fsync(2), fclose(3), ferror(3), fflush(3), fmemopen(3), fopen(3), open_memstream(3), pcap_file(3pcap), stdio(3)
Copyright and license for this manual page
|
HTML rendering created 2022-12-18 by Michael Kerrisk, author of The Linux Programming Interface, maintainer of the Linux man-pages project. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|