определения функции poll (definitions for the poll() function)
Пролог (Prolog)
This manual page is part of the POSIX Programmer's Manual. The
Linux implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
Имя (Name)
poll.h — definitions for the poll() function
Синопсис (Synopsis)
#include <poll.h>
Описание (Description)
The <poll.h> header shall define the pollfd
structure, which
shall include at least the following members:
int fd The following descriptor being polled.
short events The input event flags (see below).
short revents The output event flags (see below).
The <poll.h> header shall define the following type through
typedef
:
nfds_t
An unsigned integer type used for the number of
file descriptors.
The implementation shall support one or more programming
environments in which the width of nfds_t
is no greater than the
width of type long
. The names of these programming environments
can be obtained using the confstr() function or the getconf
utility.
The <poll.h> header shall define the following symbolic
constants, zero or more of which may be OR'ed together to form
the events or revents members in the pollfd
structure:
POLLIN Data other than high-priority data may be read
without blocking.
POLLRDNORM Normal data may be read without blocking.
POLLRDBAND Priority data may be read without blocking.
POLLPRI High priority data may be read without blocking.
POLLOUT Normal data may be written without blocking.
POLLWRNORM Equivalent to POLLOUT.
POLLWRBAND Priority data may be written.
POLLERR An error has occurred (revents only).
POLLHUP Device has been disconnected (revents only).
POLLNVAL Invalid fd member (revents only).
The significance and semantics of normal, priority, and high-
priority data are file and device-specific.
The following shall be declared as a function and may also be
defined as a macro. A function prototype shall be provided.
int poll(struct pollfd [], nfds_t, int);
The following sections are informative.
Использование в приложениях (Application usage)
None.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
None.
Смотри также (See also)
The System Interfaces volume of POSIX.1‐2017, confstr(3p),
poll(3p)
The Shell and Utilities volume of POSIX.1‐2017, getconf(1p)