1<sys/time.h>(P)            POSIX Programmer's Manual           <sys/time.h>(P)
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NAME

6       sys/time.h - time types
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SYNOPSIS

9       #include <sys/time.h>
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DESCRIPTION

12       The  <sys/time.h>  header  shall  define  the  timeval  structure  that
13       includes at least the following members:
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16              time_t         tv_sec      Seconds.
17              suseconds_t    tv_usec     Microseconds.
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19       The <sys/time.h> header  shall  define  the  itimerval  structure  that
20       includes at least the following members:
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23              struct timeval it_interval Timer interval.
24              struct timeval it_value    Current value.
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26       The  time_t  and  suseconds_t  types  shall  be defined as described in
27       <sys/types.h> .
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29       The fd_set type shall be defined as described in <sys/select.h> .
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31       The <sys/time.h> header shall define the following values for the which
32       argument of getitimer() and setitimer():
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34       ITIMER_REAL
35              Decrements in real time.
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37       ITIMER_VIRTUAL
38              Decrements in process virtual time.
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40       ITIMER_PROF
41              Decrements  both  in process virtual time and when the system is
42              running on behalf of the process.
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45       The following  shall  be  defined  as  described  in  <sys/select.h>  :
46       FD_CLR() FD_ISSET() FD_SET() FD_ZERO() FD_SETSIZE
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48       The following shall be declared as functions and may also be defined as
49       macros. Function prototypes shall be provided.
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52              int   getitimer(int, struct itimerval *);
53              int   gettimeofday(struct timeval *restrict, void *restrict);
54              int   select(int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
55                        struct timeval *restrict);
56              int   setitimer(int, const struct itimerval *restrict,
57                        struct itimerval *restrict);
58              int   utimes(const char *, const struct timeval [2]); (LEGACY )
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60       Inclusion of the <sys/time.h> header may make visible all symbols  from
61       the <sys/select.h> header.
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63       The following sections are informative.
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APPLICATION USAGE

66       None.
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RATIONALE

69       None.
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FUTURE DIRECTIONS

72       None.
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SEE ALSO

75       <sys/select.h>  ,  <sys/types.h>  ,  the  System  Interfaces  volume of
76       IEEE Std 1003.1-2001,    getitimer(),     gettimeofday(),     select(),
77       setitimer()
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80       Portions  of  this text are reprinted and reproduced in electronic form
81       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
82       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
83       Specifications Issue 6, Copyright (C) 2001-2003  by  the  Institute  of
84       Electrical  and  Electronics  Engineers, Inc and The Open Group. In the
85       event of any discrepancy between this version and the original IEEE and
86       The  Open Group Standard, the original IEEE and The Open Group Standard
87       is the referee document. The original Standard can be  obtained  online
88       at http://www.opengroup.org/unix/online.html .
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92IEEE/The Open Group                  2003                      <sys/time.h>(P)
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