$NetBSD: patch-qmail-qfilter.1,v 1.1 2022/03/01 19:15:38 schmonz Exp $

Apply all upstream changes since 2.1 (aff0c4a) through master (795718f).

--- qmail-qfilter.1.orig	2005-08-12 23:40:51.000000000 +0000
+++ qmail-qfilter.1
@@ -11,13 +11,13 @@ qmail-qfilter \- front end for qmail-que
 .B qmail-qfilter
 sends the message text through each of the filter commands named on
 the command line. 
-Each filter is run seperately, with standard input opened to the input
+Each filter is run separately, with standard input opened to the input
 email, and standard output opened to a new temporary file that will
 become the input to either the next filter, or
 .BR qmail-queue .
 If the filter does not modify the message it passes unchanged to the
 next step.
-It also makes the envelope avaliable to each filter as
+It also makes the envelope available to each filter as
 file descriptor 3.  File descriptor 4 is opened to a new temporary file for the
 modified envelope, allowing the filter to modify the envelope or the
 message.  If the filter does not modify the envelope, the envelope
@@ -27,10 +27,10 @@ This provides compatibility for existing
 the envelope.
 .B qmail-qfilter
 also opens up file descriptor 5 to a temporary file.  If this file is
-empty after all the filters have executed, its contents are read and
+not empty after all the filters have executed, its contents are read and
 used to specify a program to execute in place of
 .BR qmail-queue .
-Each filter on the command line in seperated with
+Each filter on the command line is separated with
 .BR -- .  
 .SH "RETURN VALUES"
 Returns 51 (out of memory), 53 (write error), or 81 (internal error)
@@ -47,7 +47,14 @@ returns 0 immediately without running an
 Otherwise returns the exit code of
 .BR qmail-queue .
 .SH ENVIRONMENT
-For cmpatibility with previous versions,
+.B qmail-qfilter
+sets
+.B QMAILPPID
+to the PID of its parent (e.g.,
+.BR qmail-smtpd )
+so that a filter can log the PID of the session that invoked it.
+.P
+For compatibility with previous versions,
 .B qmail-qfilter
 sets
 .B QMAILUSER
@@ -95,17 +102,17 @@ and
 by using
 .B env -u QMAILNAME -u MAILNAME -u NAME qmail-inject -n
 as the command to invoke qmail-inject.
-Note that some the
+Note that the
 .B env
-command with some OS's doesn't support the
+command with some OSes doesn't support the
 .B -u
 option.
 .P
 A message with an excessive number of recipients (more than 64K bytes of
 recipient data on Linux) will cause execution of the filter programs to
-fail, and for the message to be rejected.
+fail, and the message to be rejected.
 .P
 The same temporary file is reused for file descriptor 5 for each filter.
 Make sure each filter writes a trailing ASCII NUL byte following the
 program name, as multiple filters could otherwise overwrite the value in
-undesireable ways.
+undesirable ways.