Is there any function like clock() in c in php?

I want to measure the execution time for ph开发者_如何学Pythonp script~

Use microtime. Make sure to look at example #2.

With microtime: example

mixed microtime ([ bool $get_as_float ] )

microtime() returns the current Unix timestamp with microseconds. This function is only available on operating systems that support the gettimeofday() system call.

As long as PHP is running on a Unix system, you can get a fairly accurate measurement of the time taken using the time(1) command. See the manpage for usage and output information.

If you want to time a specific section of the script, for whatever reason, I would personally just copy/paste it into its own file and run time(1) on that.

If you need to use the return value within a php script, you can use output generated by time(1) from PHP by returning it into a string using either shell_exec() or the backtick (`) operator. See the PHP manual for more information on that.

As for a native PHP implementation of the clock(3) function, I don't believe such a thing exists and if it does I don't think it's part of the standard library.

The microtime function used by other answers does something different to clock(3), as has been pointed out by Steve Jessop.

function get_microtime() {
    list($usec, $sec) = explode(" ", microtime()); 
    return ((float)$usec + (float)$sec); 
}