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Process.wait
static VALUE
proc_m_wait(int c, VALUE *v, VALUE _)
{
return proc_wait(c, v);
}
Waits for a child process to exit, returns its process id, and sets $? to a Process::Status object containing information on that process. Which child it waits on depends on the value of pid:
- > 0
-
Waits for the child whose process ID equals pid.
- 0
-
Waits for any child whose process group ID equals that of the calling process.
- -1
-
Waits for any child process (the default if no pid is given).
- < -1
-
Waits for any child whose process group ID equals the absolute value of pid.
The flags argument may be a logical or of the flag values Process::WNOHANG (do not block if no child available) or Process::WUNTRACED (return stopped children that haven’t been reported). Not all flags are available on all platforms, but a flag value of zero will work on all platforms.
Calling this method raises a SystemCallError if there are no child processes. Not available on all platforms.
include Process fork { exit 99 } #=> 27429 wait #=> 27429 $?.exitstatus #=> 99 pid = fork { sleep 3 } #=> 27440 Time.now #=> 2008-03-08 19:56:16 +0900 waitpid(pid, Process::WNOHANG) #=> nil Time.now #=> 2008-03-08 19:56:16 +0900 waitpid(pid, 0) #=> 27440 Time.now #=> 2008-03-08 19:56:19 +0900