.cindex "expansion" "selecting from list by condition"
.vindex "&$item$&"
After expansion, <&'string'&> is interpreted as a list, colon-separated by
-default, but the separator can be changed in the usual way. For each item
+default, but the separator can be changed in the usual way (&<<SECTlistsepchange>>&).
+For each item
in this list, its value is place in &$item$&, and then the condition is
evaluated. If the condition is true, &$item$& is added to the output as an
item in a new list; if the condition is false, the item is discarded. The
and leading and trailing white space (which is ignored).
After expansion, <&'string1'&> is interpreted as a list, colon-separated by
-default, but the separator can be changed in the usual way.
+default, but the separator can be changed in the usual way (&<<SECTlistsepchange>>&).
The first field of the list is numbered one.
If the number is negative, the fields are
.cindex "expansion" "list creation"
.vindex "&$item$&"
After expansion, <&'string1'&> is interpreted as a list, colon-separated by
-default, but the separator can be changed in the usual way. For each item
+default, but the separator can be changed in the usual way (&<<SECTlistsepchange>>&).
+For each item
in this list, its value is place in &$item$&, and then <&'string2'&> is
expanded and added to the output as an item in a new list. The separator used
for the output list is the same as the one used for the input, but a separator
.vindex "&$item$&"
This operation reduces a list to a single, scalar string. After expansion,
<&'string1'&> is interpreted as a list, colon-separated by default, but the
-separator can be changed in the usual way. Then <&'string2'&> is expanded and
+separator can be changed in the usual way (&<<SECTlistsepchange>>&).
+Then <&'string2'&> is expanded and
assigned to the &$value$& variable. After this, each item in the <&'string1'&>
list is assigned to &$item$&, in turn, and <&'string3'&> is expanded for each of
them. The result of that expansion is assigned to &$value$& before the next
.cindex list sorting
.cindex expansion "list sorting"
After expansion, <&'string'&> is interpreted as a list, colon-separated by
-default, but the separator can be changed in the usual way.
+default, but the separator can be changed in the usual way (&<<SECTlistsepchange>>&).
The <&'comparator'&> argument is interpreted as the operator
of a two-argument expansion condition.
The numeric operators plus ge, gt, le, lt (and ~i variants) are supported.
.vindex "&$item$&"
These conditions iterate over a list. The first argument is expanded to form
the list. By default, the list separator is a colon, but it can be changed by
-the normal method. The second argument is interpreted as a condition that is to
+the normal method (&<<SECTlistsepchange>>&).
+The second argument is interpreted as a condition that is to
be applied to each item in the list in turn. During the interpretation of the
condition, the current list item is placed in a variable called &$item$&.
.ilist
.endlist
The default list separator in both cases is a colon, but this can be changed as
-described in section &<<SECTlistconstruct>>&. When IPv6 addresses are involved,
+described in section &<<SECTlistsepchange>>&. When IPv6 addresses are involved,
it is usually best to change the separator to avoid having to double all the
colons. For example:
.code
exim.
The value of &%-oX%& is a list of items. The default colon separator can be
-changed in the usual way if required. If there are any items that do not
+changed in the usual way (&<<SECTlistsepchange>>&) if required.
+If there are any items that do not
contain dots or colons (that is, are not IP addresses), the value of
&%daemon_smtp_ports%& is replaced by the list of those items. If there are any
items that do contain dots or colons, the value of &%local_interfaces%& is
option in the relevant &(smtp)& transport.
&*Note*&: If you use filenames based on IP addresses, change the list
-separator in the usual way to avoid confusion under IPv6.
+separator in the usual way (&<<SECTlistsepchange>>&) >to avoid confusion under IPv6.
&*Note*&: Under versions of OpenSSL preceding 1.1.1,
when a list of more than one
.cindex "fallback" "hosts specified on router"
String expansion is not applied to this option. The argument must be a
colon-separated list of host names or IP addresses. The list separator can be
-changed (see section &<<SECTlistconstruct>>&), and a port can be specified with
+changed (see section &<<SECTlistsepchange>>&), and a port can be specified with
each name or address. In fact, the format of each item is exactly the same as
defined for the list of hosts in a &(manualroute)& router (see section
&<<SECTformatonehostitem>>&).
.cindex "header lines" "adding"
.cindex "router" "adding header lines"
This option specifies a list of text headers,
-newline-separated (by default, changeable in the usual way),
+newline-separated (by default, changeable in the usual way &<<SECTlistsepchange>>&),
that is associated with any addresses that are accepted by the router.
Each item is separately expanded, at routing time. However, this
option has no effect when an address is just being verified. The way in which
.cindex "header lines" "removing"
.cindex "router" "removing header lines"
This option specifies a list of text headers,
-colon-separated (by default, changeable in the usual way),
+colon-separated (by default, changeable in the usual way &<<SECTlistsepchange>>&),
that is associated with any addresses that are accepted by the router.
Each item is separately expanded, at routing time. However, this
option has no effect when an address is just being verified. The way in which
through the &%require_files%& list, expanding each item separately.
Because the list is split before expansion, any colons in expansion items must
-be doubled, or the facility for using a different list separator must be used.
+be doubled, or the facility for using a different list separator must be used
+(&<<SECTlistsepchange>>&).
If any expansion is forced to fail, the item is ignored. Other expansion
failures cause routing of the address to be deferred.
If the list is written with spaces, it must be protected with quotes.
The format of each item
in the list is described in the next section. The list separator can be changed
-as described in section &<<SECTlistconstruct>>&.
+as described in section &<<SECTlistsepchange>>&.
If the list of hosts was obtained from a &%route_list%& item, the following
variables are set during its expansion:
.cindex "header lines" "adding in transport"
.cindex "transport" "header lines; adding"
This option specifies a list of text headers,
-newline-separated (by default, changeable in the usual way),
+newline-separated (by default, changeable in the usual way &<<SECTlistsepchange>>&),
which are (separately) expanded and added to the header
portion of a message as it is transported, as described in section
&<<SECTheadersaddrem>>&. Additional header lines can also be specified by
.cindex "header lines" "removing"
.cindex "transport" "header lines; removing"
This option specifies a list of header names,
-colon-separated (by default, changeable in the usual way);
+colon-separated (by default, changeable in the usual way &<<SECTlistsepchange>>&);
these headers are omitted from the message as it is transported, as described
in section &<<SECTheadersaddrem>>&. Header removal can also be specified by
routers.
during the expansion of the string. Forced expansion failure, or an empty
string result causes the option to be ignored. Otherwise, after expansion, the
string must be a list of IP addresses, colon-separated by default, but the
-separator can be changed in the usual way. For example:
+separator can be changed in the usual way (&<<SECTlistsepchange>>&).
+For example:
.code
interface = <; 192.168.123.123 ; 3ffe:ffff:836f::fe86:a061
.endd
condition succeeds if a virus is found and its name matches the regular
expression. This allows you to take special actions on certain types of virus.
Note that &"/"& characters in the RE must be doubled due to the list-processing,
-unless the separator is changed (in the usual way).
+unless the separator is changed (in the usual way &<<SECTlistsepchange>>&).
.endlist
You can append a &`defer_ok`& element to the &%malware%& argument list to accept
You can have multiple &%spamd%& servers to improve scalability. These can
reside on other hardware reachable over the network. To specify multiple
&%spamd%& servers, put multiple address/port pairs in the &%spamd_address%&
-option, separated with colons (the separator can be changed in the usual way):
+option, separated with colons (the separator can be changed in the usual way &<<SECTlistsepchange>>&):
.code
spamd_address = 192.168.2.10 783 : \
192.168.2.11 783 : \
Unix and TCP socket specifications may be mixed in any order.
Each element of the list is a list itself, space-separated by default
-and changeable in the usual way; take care to not double the separator.
+and changeable in the usual way (&<<SECTlistsepchange>>&);
+take care to not double the separator.
For TCP socket specifications a host name or IP (v4 or v6, but
subject to list-separator quoting rules) address can be used,