подождите, пока дочерний процесс остановится или завершится (wait for a child process to stop or terminate)
Использование в приложениях (Application usage)
Calls to wait() will collect information about any child process.
This may result in interactions with other interfaces that may be
waiting for their own children (such as by use of system()). For
this and other reasons it is recommended that portable
applications not use wait(), but instead use waitpid(). For
these same reasons, the use of waitpid() with a pid argument of
-1, and the use of waitid() with the idtype argument set to
P_ALL, are also not recommended for portable applications.
As specified in Consequences of Process Termination, if the
calling process has SA_NOCLDWAIT set or has SIGCHLD set to
SIG_IGN, then the termination of a child process will not cause
status information to become available to a thread blocked in
wait(), waitid(), or waitpid(). Thus, a thread blocked in one of
the wait functions will remain blocked unless some other
condition causes the thread to resume execution (such as an
[ECHILD] failure due to no remaining children in the set of
waited-for children).
