The _time function returns the number of elapsed seconds since
00:00:00 GMT, January 1, 1970. The ctime function may be used
to convert this into a string representation.
The gmtime function is exactly like localtime except
that the values in the structure it returns are with respect to GMT
instead of the local timezone. See the documentation for
localtime for more information.
Notes
On systems that do not support the gmtime C library function,
this function is the same as localtime.
The localtime function takes a parameter secs
representing the number of seconds since 00:00:00, January 1 1970
UTC and returns a structure containing information about secs
in the local timezone. The structure contains the following
Int_Type fields:
tm_sec The number of seconds after the minute, normally
in the range 0 to 59, but can be up to 61 to allow for
leap seconds.
tm_min The number of minutes after the hour, in the
range 0 to 59.
tm_hour The number of hours past midnight, in the range
0 to 23.
tm_mday The day of the month, in the range 1 to 31.
tm_mon The number of months since January, in the range
0 to 11.
tm_year The number of years since 1900.
tm_wday The number of days since Sunday, in the range 0
to 6.
tm_yday The number of days since January 1, in the
range 0 to 365.
tm_isdst A flag that indicates whether daylight saving
time is in effect at the time described. The value is
positive if daylight saving time is in effect, zero if it
is not, and negative if the information is not available.
The toc function returns the elapsed CPU time in seconds since
the last call to tic. The CPU time is the amount of time the
CPU spent running the code of the current process.
Example
The tic and toc functions are ideal for timing the
execution of the interpreter:
variable a = "hello", b = "world", c, n = 100000, t;
tic (); loop (n) c = a + b; t = toc ();
vmessage ("a+b took %f seconds\n", t);
tic (); loop (n) c = strcat(a,b); t = toc ();
vmessage ("strcat took %f seconds\n", t);
Notes
This function may not be available on all systems.
The implementation of this function is based upon the times
system call. The precision of the clock is system dependent.