Add pwait utility, which waits for any process to terminate.

This is similar to the Solaris utility of the same name.

Some use cases:
* rc.subr's wait_for_pids
* interactive use, e.g. to shut down the computer when some task is done
  even if the task is already running

Discussed on:	hackers@

1 files changed, 1 insertions, 0 deletions

diff --git a/bin/Makefile b/bin/Makefile
index 7491be9..3114e67 100644
--- a/bin/Makefile
+++ b/bin/Makefile
@@ -27,6 +27,7 @@ SUBDIR= cat \
 	pax \
 	pkill \
 	ps \
+	pwait \
 	pwd \
 	${_rcp} \
 	realpath \