sys_select.h(0p) — Linux manual page


sys_select.h(0P)        POSIX Programmer's Manual       sys_select.h(0P)

PROLOG         top

       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         top

       sys/select.h — select types

SYNOPSIS         top

       #include <sys/select.h>

DESCRIPTION         top

       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

       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

       The following shall be declared as functions, defined as macros,
       or both. If functions are declared, function prototypes shall be

           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.



RATIONALE         top




SEE ALSO         top

       signal.h(0p), sys_time.h(0p), sys_types.h(0p), time.h(0p)

       The System Interfaces volume of POSIX.1‐2017, pselect(3p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 by the Institute of Electrical and Electronics
       Engineers, Inc and The Open Group.  In the event of any
       discrepancy between this version and the original IEEE and The
       Open Group Standard, the original IEEE and The Open Group
       Standard is the referee document. The original Standard can be
       obtained online at .

       Any typographical or formatting errors that appear in this page
       are most likely to have been introduced during the conversion of
       the source files to man page format. To report such errors, see .

IEEE/The Open Group               2017                  sys_select.h(0P)

Pages that refer to this page: sys_time.h(0p)pselect(3p)