FpWaitPid¶

Wait for a process to terminate.

Declaration¶

Source position: bunxh.inc line 77

function FpWaitpid(pid: TPid; stat_loc: pcint; options: cint) : TPid;external name 'FPC_SYSC_WAITPID';

function FpWaitPid(pid: TPid; var Status: cint; Options: cint) : TPid;

fpWaitPid waits for a child process with process ID Pid to exit. The value of Pid can be one of the following:

Pid < -1: Causes fpWaitPid to wait for any child process whose process group ID equals the absolute value of pid.
Pid = -1: Causes fpWaitPid to wait for any child process.
Pid = 0: Causes fpWaitPid to wait for any child process whose process group ID equals the one of the calling process.
Pid > 0: Causes fpWaitPid to wait for the child whose process ID equals the value of Pid.

The Options parameter can be used to specify further how fpWaitPid behaves:

WNOHANG: Causes fpWaitpid to return immediately if no child hasexited.
WUNTRACED: Causes fpWaitPid to return also for children which are stopped, but whose status has not yet been reported.
__WCLONE: Causes fpWaitPid also to wait for threads created by the #rtl.linux.Clone call.

The exit status of the process that caused fpWaitPID is reported in stat_loc or Status.

Upon return, it returns the process id of the process that exited, 0 if no process exited, or -1 in case of failure.

For an example, see fpFork.

Extended error information can be retrieved using fpgetErrno.

Name	Description
fpFork	Create child process.
fpExecve	Execute process using environment.
fpWait	Wait for a child to exit.