sys_select.h (0p)

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.
 

NAME

sys/select.h — select types

SYNOPSIS

#include <sys/select.h>

DESCRIPTION

The <sys/select.h> header shall define the timeval structure, which shall include at least the following members:
 

time_t tv_sec Seconds.
suseconds_t tv_usec Microseconds.
The <sys/select.h> header shall define the time_t and suseconds_t types as described in <sys/types.h>.
The <sys/select.h> header shall define the sigset_t type as described in <signal.h>.
The <sys/select.h> header shall define the timespec structure as described in <time.h>.
The <sys/select.h> header shall define the fd_set type as a structure.
The <sys/select.h> header shall define the following symbolic constant, which shall have a value suitable for use in #if preprocessing directives:
FD_SETSIZE
Maximum number of file descriptors in an fd_set structure.
The following shall be declared as functions, defined as macros, or both. If functions are declared, function prototypes shall be provided.
 

void FD_CLR(int, fd_set *);
int FD_ISSET(int, fd_set *);
void FD_SET(int, fd_set *);
void FD_ZERO(fd_set *);
If implemented as macros, these may evaluate their arguments more than once, so applications should ensure that the arguments they supply are never expressions with side-effects.
The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.
 

int pselect(int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
 const struct timespec *restrict, const sigset_t *restrict);
int select(int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
 struct timeval *restrict);
Inclusion of the <sys/select.h> header may make visible all symbols from the headers <signal.h> and <time.h>.
The following sections are informative.

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

<signal.h>, <sys_time.h>, <sys_types.h>, <time.h>
The System Interfaces volume of POSIX.1‐2008, pselect()

Information

Source
POSIX
OS/version
IEEE/The Open Group
Source updated
January 1, 2013
Page created
March 3, 2018
Page generated
March 4, 2018