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

       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() FD_SETSIZE

       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.1‐2008, 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, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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                 2013                      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)utimes(3p)