16.7.11 Extension Time Functions

The time extension adds two functions, named gettimeofday() and sleep(), as follows:

@load "time"

This is how you load the extension.

the_time = gettimeofday()

Return the time in seconds that has elapsed since 1970-01-01 UTC as a floating-point value. If the time is unavailable on this platform, return -1 and set ERRNO. The returned time should have sub-second precision, but the actual precision may vary based on the platform. If the standard C gettimeofday() system call is available on this platform, then it simply returns the value. Otherwise, if on MS-Windows, it tries to use GetSystemTimeAsFileTime().

result = sleep(seconds)

Attempt to sleep for seconds seconds. If seconds is negative, or the attempt to sleep fails, return -1 and set ERRNO. Otherwise, return zero after sleeping for the indicated amount of time. Note that seconds may be a floating-point (nonintegral) value. Implementation details: depending on platform availability, this function tries to use nanosleep() or select() to implement the delay.