pcntl_wait
(no version information, might be only in CVS)
pcntl_wait -- Waits on or returns the status of a forked
child
Description
int pcntl_wait ( int &status [, int options])
The wait function suspends execution of the current process
until a child has exited, or until a signal is delivered
whose action is to terminate the current process or to call
a signal handling function. If a child has already exited
by the time of the call (a so-called "zombie"
process), the function returns immediately. Any system resources
used by the child are freed. Please see your system's wait(2)
man page for specific details as to how wait works on your
system.
pcntl_wait() returns the process ID of the child which
exited, -1 on error or zero if WNOHANG was provided as an
option (on wait3-available systems) and no child was available.
If wait3 is available on your system (mostly BSD-style
systems), you can provide the optional options parameter.
If this parameter is not provided, wait will be used for
the system call. If wait3 is not available, providing a
value for options will have no effect. The value of options
is the value of zero or more of the following two constants
OR'ed together:
Table 1. Possible values for options if wait3 is available
WNOHANG Return immediately if no child has exited.
WUNTRACED Return for children which are stopped, and whose
status has not been reported.
pcntl_wait() will store status information in the status
parameter which can be evaluated using the following functions:
pcntl_wifexited(), pcntl_wifstopped(), pcntl_wifsignaled(),
pcntl_wexitstatus(), pcntl_wtermsig() and pcntl_wstopsig().
Note: This function is equivalent to calling pcntl_waitpid()
with a -1 pid and no options.
See also pcntl_fork(), pcntl_signal(), pcntl_wifexited(),
pcntl_wifstopped(), pcntl_wifsignaled(), pcntl_wexitstatus(),
pcntl_wtermsig(), pcntl_wstopsig() and pcntl_waitpid().
