sleep

Delay execution

&reftitle.description; `int` `sleep` `int` `seconds`

Delays the program execution for the given number of `seconds`.

In order to delay program execution for a fraction of a second, use `usleep` as the `sleep` function expects an &integer;. For example, `sleep(0.25)` will pause program execution for `0` seconds.

&reftitle.parameters;

`seconds`

- Halt time in seconds (must be greater than or equal to `0`).

&reftitle.returnvalues;

Returns zero on success.

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.

&reftitle.errors;

If the specified number of `seconds` is negative, this function will throw a `ValueError`.

&reftitle.changelog;

&Version; | &Description;
8.0.0 | The function throws a `ValueError` on negative `seconds`; previously, an `E_WARNING` was raised instead, and the function returned &false;.

&reftitle.examples;

### `sleep` example

    <?php

    // current time
    echo date('h:i:s') . "\n";

    // sleep for 10 seconds
    sleep(10);

    // wake up !
    echo date('h:i:s') . "\n";

    ?>

This example will output (after 10 seconds)

    05:31:23
    05:31:33

&reftitle.seealso;

- `usleep`
- `time_nanosleep`
- `time_sleep_until`
- `set_time_limit`