PHP sleep () function, usleep () function, sleepusleep

PHP sleep () function, usleep () function, sleepusleep

PHP sleep () function

Definition and usage

The sleep () function delays code execution for several seconds.
Syntax sleep (seconds)

Seconds required. The pause time in seconds.
Return Value

If the call succeeds, 0 is returned. Otherwise, false is returned.
Error/exception

If the specified description seconds is a negative number, this function generates an E_WARNING.

Example

<? Php echo date ('H: I: s '). "<br/>"; // pause sleep (10) for 10 seconds; // restart echo date ('H: I: s');?>

Output:

12:00:08 12:00:18

PHP usleep () function

Definition and usage

The usleep () function delays code execution in several microseconds.
Syntax: usleep (microseconds)

Microseconds is required. The pause time in microseconds.
Return Value

No return value.
Tips and comments

Note: Before PHP 5, this function cannot work on Windows.

Note: one microsecond equals to one second per million.
Example

<? Php echo date ('H: I: s '). "<br/>"; // delay 10 description usleep (10000000); // start echo date again ('H: I: s');?>

Output:
09:23:14 09:23:24

Usage of sleep and unsleep in PHP

When you need to suspend the program for several seconds, you can use sleep.

Int sleep (int $ seconds) is paused for $ seconds and then executed.

Returns zero on success, or FALSE on error. 0 is returned for success, and false is returned for error.

If the call was interrupted by a signal, sleep () returns a non-zero value. on Windows, this value will always be 192 (the value of the WAIT_IO_COMPLETION constant within the Windows API ). on other platforms, the return value will be the number of seconds left to sleep.

If the call is interrupted, this function returns a non-zero value. On windows, this value is always 192 (this value is a constant value in Windows API waiting for IO to complete WAIT_IO_COMPLETION ). The return value for other platforms is the number of seconds when sleep has not been executed.

If the specified number of seconds is negative, this function will generate a E_WARNING.

If the parameter is negative, the function produces a warning error.

When you need to suspend the execution for 1 second, you can use usleep.

Void usleep (int $ micro_seconds)

Delays program execution for the given number of micro seconds.

The usleep parameter is in microseconds and has no return value.

You can use

Time_nanosleep ()-Delay for a number of seconds and nanoseconds

You can use

Time_sleep_until ()-Make the script sleep until the specified time