gettimeofday()--Get Current UTC Time
Syntax
#include <sys/time.h>
int gettimeofday (struct timeval *tp,
struct timezone *tzp);
Service Program Name:QWCTZUTC
Default Public Authority: *USE
Threadsafe: Yes
The gettimeofday() function retrieves the current Coordinated Universal Time (UTC) and places it in the timeval structure pointed to by tp. If tzp is not NULL, the time zone information is returned in the time zone structure pointed to by tzp.
Parameters
- tp
- (Output) A pointer to a timeval structure that contains the time in seconds
and microseconds since 1 January 1970, 00:00:00 UTC (epoch-1970).
- tzp
- (Output) A pointer to a time zone structure that contains the local time zone (measured in minutes west of Greenwich) and a flag that, if nonzero, indicates Daylight Saving Time applies locally during the appropriate part of the year.
Authorities and Locks
None.
Return Value
| 0 | gettimeofday() was
successful. |
| -1 | gettimeofday() was not successful. The errno variable is set to indicate the error. |
Error Conditions
If gettimeofday() is not successful, errno usually indicates one of the following errors. Under some conditions, errno could indicate an error other than those listed here.
| [EINVAL] | An invalid parameter was found.
A parameter passed to this function is not valid. |
| [EFAULT] | The address used for an argument is not correct.
In attempting to use an argument in a call, the system detected an address that is not valid. While attempting to access a parameter passed to this function, the system detected an address that is not valid. |
| [EUNKNOWN] | Unknown system state.
The operation failed because of an unknown system state. See any messages in the job log and correct any errors that are indicated, then retry the operation. |
Error Messages
None.
Usage Notes
- For the best performance, specify NULL for the tzp parameter.
Related Information
- The <sys/time.h> file (see Header Files for UNIX®-Type Functions)
- adjtime()--Adjust System Clock
- ftime()--Get Date and Time
- Qp0zCvtToMITime()--Convert Timeval Structure to _MI_ Time
- settimeofday()--Set System Clock
Example
The following example gets the current UTC time.
Note: By using the code examples, you agree to the terms of the Code license and disclaimer information.
#include <sys/time.h>
#include <stdio.h>
#include <errno.h>
int main(int argc, char *argv[])
{
struct timeval now;
int rc;
rc=gettimeofday(&now, NULL);
if(rc==0) {
printf("gettimeofday() successful.\n");
printf("time = %u.%06u\n",
now.tv_sec, now.tv_usec);
}
else {
printf("gettimeofday() failed, errno = %d\n",
errno);
return -1;
}
return 0;
}
Example Output:
gettimeofday() successful. time = 866208142.290944
API introduced: V4R2