Fix -p doc mention of Perl -pd conflict.

[exim.git] / doc / doc-docbook / spec.xfpt

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index c3994a79cb194f6dbaaac270875440f4dc1e646c..063d74a9290ed79e066af496c627561767828932 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -4335,7 +4335,7 @@ For compatibility with Sendmail, this option is equivalent to
 It sets the incoming protocol and host name (for trusted callers). The
 host name and its colon can be omitted when only the protocol is to be set.
 Note the Exim already has two private options, &%-pd%& and &%-ps%&, that refer
-to embedded Perl. It is therefore impossible to set a protocol value of &`p`&
+to embedded Perl. It is therefore impossible to set a protocol value of &`d`&
 or &`s`& using this option (but that does not seem a real limitation).
 
 .vitem &%-q%&
@@ -21712,11 +21712,14 @@ inserted in the argument list at that point &'as a separate argument'&. This
 avoids any problems with spaces or shell metacharacters, and is of use when a
 &(pipe)& transport is handling groups of addresses in a batch.
 
-If &(force_command)& is enabled on the transport, Special handling takes place
+If &%force_command%& is enabled on the transport, Special handling takes place
 for an argument that consists of precisely the text &`$address_pipe`&.  It
-is handled much like &`$pipe_addresses`& above.  It is expanded and each
+is handled similarly to &$pipe_addresses$& above.  It is expanded and each
 argument is inserted in the argument list at that point
-&'as a separate argument'&.
+&'as a separate argument'&.  The &`$address_pipe`& item does not need to be
+the only item in the argument; in fact, if it were then &%force_command%&
+should behave as a no-op.  Rather, it should be used to adjust the command
+run while preserving the argument vector separation.
 
 After splitting up into arguments and expansion, the resulting command is run
 in a subprocess directly from the transport, &'not'& under a shell. The
@@ -21883,6 +21886,10 @@ command = /usr/bin/remote_exec myhost -- $address_pipe
 force_command
 .endd
 
+Note that &$address_pipe$& is handled specially in &%command%& when
+&%force_command%& is set, expanding out to the original argument vector as
+separate items, similarly to a Unix shell &`"$@"`& construct.
+
 .option ignore_status pipe boolean false
 If this option is true, the status returned by the subprocess that is set up to
 run the command is ignored, and Exim behaves as if zero had been returned.