Content-type: text/html Man page of gettimeofday

gettimeofday

Section: System Calls (2)
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NAME

gettimeofday, settimeofday, ftime - Gets and sets date and time  

SYNOPSIS

#include <sys/time.h>

int gettimeofday( struct timeval *tp, void *tzp ); #include <sys/timeb.h>

int ftime( struct timeb *tp );

The following function declarations do not conform to current standards and are supported only for backward compatibility: #include <sys/time.h>

int gettimeofday( struct timeval *tp, struct timezone *tzp ); int *settimeofday( struct timeval *tp, struct timezone *tzp );
 

LIBRARY

Standard C Library (libc)
 

STANDARDS

Interfaces documented on this reference page conform to industry standards as follows:

gettimeofday(), ftime():  XPG4-UNIX

Refer to the standards(5) reference page for more information about industry standards and associated tags.
 

PARAMETERS

For gettimeofday() and settimeofday(), points to a timeval structure, defined in the <sys/time.h> file.

For ftime(), points to a timeb structure, defined in the <sys/timeb.h> file. [Compaq]  For the backward-compatible versions of gettimeofday() and settimeofday(), points to a timezone structure, defined in the <sys/time.h> file.
 

DESCRIPTION

The gettimeofday(), ftime(), and settimeofday() functions get and set the time and timezone information stored in the kernel.

The gettimeofday() function gets the current time, expressed in seconds and microseconds since midnight (0 hour), January 1, 1970 UTC (Coordinated Universal Time, formerly Greenwich Mean Time or GMT), and stores it in the timeval structure pointed to by tp.

The ftime() function sets the time and millitm members of the timeb structure pointed to by tp to contain the seconds and milliseconds portions, respectively, of the current time in seconds since midnight (0 hour), January 1, 1970 UTC.

See the NOTES section for information on the backward-compatible versions of gettimeofday() and settimeofday().

See the timezone(3) reference page for information on timezone handling on Tru64 UNIX systems.
 

NOTES

The following information applies only to the backward-compatible versions of the gettimeofday() and settimeofday() functions.

[Compaq]  The timezone structure that is returned for the gettimeofday() call is set at boot time by the /sbin/init.d/settime script. The tz_minuteswest field of the structure is set to your local time zone. This field is set only for backward compatibility with older applications that may use the gettimeofday() call for timezone information. The tz_dsttime field is set to zero because this field is obsolete.

[Compaq]  On SVID2-compatible systems, local timezone information is maintained in the kernel, although the information is not as accurate or as complete as the information that can be maintained at user level. On these systems, you can use the tzp parameter with gettimeofday() and settimeofday() to get and set timezone information in addition to the time. The tzp parameter returns a pointer to a timezone structure that contains the local timezone expressed in minutes of time westward from Greenwich and a flag that, when nonzero, indicates that daylight savings time applies locally during some part of the year. Note that, if the tzp parameter is set to NULL, timezone information is not returned or set.

[Compaq]  A process must have the sysattr effective privilege to use settimeofday().
 

RETURN VALUES

Upon successful completion, a value of 0 (zero) is returned. Otherwise, -1 is returned and errno is set to indicate the error.
 

ERRORS

If the gettimeofday() or settimeofday() function fails, errno may be set the following value: [Compaq]  A parameter points to an invalid address. [Compaq]  The process's effective user ID does not have the sysattr effective privilege, which is required for using settimeofday().
 

SEE ALSO

Commands:  date(1), zdump(8), zic(8)

Functions:  adjtime(2), ctime(3), getclock(3), gettimer(3), setclock(3), strftime(3), timezone(3)

Files:  tzfile(4)

Standards:  standards(5)


 

Index

NAME
SYNOPSIS
LIBRARY
STANDARDS
PARAMETERS
DESCRIPTION
NOTES
RETURN VALUES
ERRORS
SEE ALSO

This document was created by man2html, using the manual pages.
Time: 02:40:17 GMT, October 02, 2010