pcntl_waitid

Waits for a child process to change state.

pcntl_waitid Function synopsis

pcntl_waitid(
    int $idtype = P_ALL,
    ?int $id = null,
    &$info = [],
    int $flags = WEXITED,
    &$resource_usage = []
  ): bool

Parameters

$idtype

OptionalTypeintDefault valueP_ALL

$id

OptionalType?intDefault valuenull

$info

Passed by reference, OptionalDefault value[]

The $info parameter is set to an array containing information about the signal.

$flags

OptionalTypeintDefault valueWEXITED

The value of $flags is the value of zero or more of the following constants OR'ed together:

$resource_usage

Passed by reference, OptionalDefault value[]

Note that the parameters $info and $resource_usage are passed by reference, and contain additional/updated context data that may be useful.

Return value

Typebool

pcntl_waitid returns true if WNOHANG was specified and status is not available for any process specified by $idtype and $id.

pcntl_waitid returns true due to the change of state of one of its children.

Otherwise, false is returned and pcntl_get_last_error can be used to get the errno error number.

Once an `errno` error number has been obtained,
[`pcntl_strerror`](/codex/pcntl_strerror) can be used to get the text message
associated with it.