sys_time.h(0p) — Linux manual page


sys_time.h(0P)          POSIX Programmer's Manual         sys_time.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/time.h — time types

SYNOPSIS         top

       #include <sys/time.h>

DESCRIPTION         top

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

           struct timeval it_interval Timer interval.
           struct timeval it_value    Current value.

       The <sys/time.h> header shall define the time_t and suseconds_t
       types as described in <sys/types.h>.

       The <sys/time.h> header shall define the fd_set type as described
       in <sys/select.h>.

       The <sys/time.h> header shall define the following symbolic
       constants for the which argument of getitimer() and setitimer():

       ITIMER_REAL   Decrements in real time.

                     Decrements in process virtual time.

       ITIMER_PROF   Decrements both in process virtual time and when
                     the system is running on behalf of the process.

       The <sys/time.h> header shall define the following as described
       in <sys/select.h>: FD_CLR() FD_ISSET() FD_SET() FD_ZERO()

       The following shall be declared as functions and may also be
       defined as macros. Function prototypes shall be provided.

           int   getitimer(int, struct itimerval *);
           int   gettimeofday(struct timeval *restrict, void *restrict);
           int   setitimer(int, const struct itimerval *restrict,
                     struct itimerval *restrict);
           int   select(int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
                     struct timeval *restrict);
           int   utimes(const char *, const struct timeval [2]);

       Inclusion of the <sys/time.h> header may make visible all symbols
       from the <sys/select.h> header.

       The following sections are informative.



RATIONALE         top




SEE ALSO         top

       sys_select.h(0p), sys_types.h(0p)

       The System Interfaces volume of POSIX.1‐2017, futimens(3p),
       getitimer(3p), gettimeofday(3p), 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_time.h(0P)

Pages that refer to this page: sys_resource.h(0p)sys_select.h(0p)utmpx.h(0p)futimens(3p)getitimer(3p)gettimeofday(3p)pselect(3p)