The fact is simple: Subshells have the same PPID as the current shell.

What is not so simple is squinting hard enough to conclude that POSIX
actually says that. I'm still not sure how to do that.
Problem with the shell manual pointed out by "Choose a display name".

ok otto, halex, jmc

diff --git a/bin/ksh/sh.1 b/bin/ksh/sh.1
index c7ea82a..7ea6cfa 100644 (file)
--- a/bin/ksh/sh.1
+++ b/bin/ksh/sh.1
@@ -1,4 +1,4 @@
-.\"    $OpenBSD: sh.1,v 1.142 2017/05/26 11:45:57 jmc Exp $
+.\"    $OpenBSD: sh.1,v 1.143 2017/06/01 20:37:38 tb Exp $
 .\"
 .\" Copyright (c) 2015 Jason McIntyre <jmc@openbsd.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: May 26 2017 $
+.Dd $Mdocdate: June 1 2017 $
 .Dt SH 1
 .Os
 .Sh NAME
@@ -2093,7 +2093,7 @@ Enable POSIX mode
 The shell's parent process ID.
 Subshells have the same
 .Ev PPID
-as the parent of the current shell.
+as the current shell.
 .It Ev PS1
 User prompt displayed every time an interactive shell
 is ready to read a command.