X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/b01dd148c3a5f3a70817b08e41ad21aeee1d8f28..a43a27c5e355a06131c36e68a63a0609b1da8307:/doc/doc-txt/NewStuff diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff index 3fe06394f..bd43aecf8 100644 --- a/doc/doc-txt/NewStuff +++ b/doc/doc-txt/NewStuff @@ -1,4 +1,4 @@ -$Cambridge: exim/doc/doc-txt/NewStuff,v 1.130 2007/01/23 14:34:02 ph10 Exp $ +$Cambridge: exim/doc/doc-txt/NewStuff,v 1.145 2007/03/13 15:32:47 ph10 Exp $ New Features in Exim -------------------- @@ -197,6 +197,210 @@ Version 4.67 go while a single connection is being processed. When a child process terminates, the daemon decrements the variable. + 6. There's a new control called no_pipelining, which does what its name + suggests. It turns off the advertising of the PIPELINING extension to SMTP. + To be useful, this control must be obeyed before Exim sends its response to + an EHLO command. Therefore, it should normally appear in an ACL controlled + by acl_smtp_connect or acl_smtp_helo. + + 7. There are two new variables called $sending_ip_address and $sending_port. + These are set whenever an SMTP connection to another host has been set up, + and they contain the IP address and port of the local interface that is + being used. They are of interest only on hosts that have more than on IP + address that want to take on different personalities depending on which one + is being used. + + 8. The expansion of the helo_data option in the smtp transport now happens + after the connection to the server has been made. This means that it can + use the value of $sending_ip_address (see 7 above) to vary the text of the + message. For example, if you want the string that is used for helo_data to + be obtained by a DNS lookup of the interface address, you could use this: + + helo_data = ${lookup dnsdb{ptr=$sending_ip_address}{$value}\ + {$primary_hostname}} + + The use of helo_data applies both to sending messages and when doing + callouts. + + 9. There is a new expansion operator ${rfc2047d: that decodes strings that + are encoded as per RFC 2047. Binary zero bytes are replaced by question + marks. Characters are converted into the character set defined by + headers_charset. Overlong RFC 2047 "words" are not recognized unless + check_rfc2047_length is set false. + +10. There is a new log selector called "pid", which causes the current process + id to be added to every log line, in square brackets, immediately after the + time and date. + +11. Exim has been modified so that it flushes SMTP output before implementing + a delay in an ACL. It also flushes the output before performing a callout, + as this can take a substantial time. These behaviours can be disabled by + obeying control = no_delay_flush or control = no_callout_flush, + respectively, at some earlier stage of the connection. The effect of the + new default behaviour is to disable the PIPELINING optimization in these + situations, in order to avoid unexpected timeouts in clients. + +12. There are two new expansion conditions that iterate over a list. They are + called forany and forall, and they are used like this: + + ${if forany{}{}{}{}} + ${if forall{}{}{}{}} + + The first argument is expanded, and the result is treated as a 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 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. + + - For forany, interpretation stops if the condition is true for any item, + and the yes-string is then expanded. If the condition is false for all + items in the list, the no-string is expanded. + + - For forall, interpration stops if the condition is false for any item, + and the no-string is then expanded. If the condition is true for all + items in the list, the yes-string is expanded. + + Note that negation of forany means that the condition must be false for all + items for the overall condition to succeed, and negation of forall means + that the condition must be false for at least one item. + + In this example, the list separator is changed to a comma: + + ${if forany{<, $recipients}{match{$item}{^user3@}}{yes}{no}} + + Outside a forany/forall condition, the value of $item is an empty string. + Its value is saved and restored while forany/forall is being processed, to + enable these expansion items to be nested. + +13. There's a new global option called dsn_from that can be used to vary the + contents of From: lines in bounces and other automatically generated + messages ("delivery status notifications" - hence the name of the option). + The default setting is: + + dsn_from = Mail Delivery System + + The value is expanded every time it is needed. If the expansion fails, a + panic is logged, and the default setting is used. + +14. The smtp transport has a new option called hosts_avoid_pipelining. It can + be used to suppress the use of PIPELINING to certain hosts, while still + supporting the other SMTP extensions (cf hosts_avoid_tls). + +15. By default, exigrep does case-insensitive matches. There is now a -I option + that makes it case-sensitive. This may give a performance improvement when + searching large log files. Without -I, the Perl pattern matches use the /i + option; with -I they don't. In both cases it is possible to change the case + sensitivity within the pattern using (?i) or (?-i). + +16. A number of new features have been added to string expansions to make it + easier to process lists of items, typically addresses. These are as + follows: + + * ${addresses:} + + The string (after expansion) is interpreted as a list of addresses in RFC + 2822 format, such as can be found in a To: or Cc: header line. The + operative address (local-part@domain) is extracted from each item, and the + result of the expansion is a colon-separated list, with appropriate + doubling of colons should any happen to be present in the email addresses. + Syntactically invalid RFC2822 address items are omitted from the output. + + It is possible to specify a character other than colon for the output + separator by starting the string with > followed by the new separator + character. For example: + + ${addresses:>& The Boss , sec@base.ment (dogsbody)} + + expands to "ceo@up.stairs&sec@base.ment". Compare ${address (singular), + which extracts the working address from a single RFC2822 address. + + * ${map{}{}} + + After expansion, is interpreted as a list, colon-separated by + default, but the separator can be changed in the usual way. For each item + in this list, its value is place in $item, and then 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 is not + included in the output. For example: + + ${map{a:b:c}{[$item]}} ${map{<- x-y-z}{($item)}} + + expands to "[a]:[b]:[c] (x)-(y)-(z)". At the end of the expansion, the + value of $item is restored to what it was before. + + * ${filter{}{}} + + After expansion, is interpreted as a list, colon-separated by + default, but the separator can be changed in the usual way. 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 + separator used for the output list is the same as the one used for the + input, but is not included in the output. For example: + + ${filter{a:b:c}{!eq{$item}{b}} + + yields "a:c". At the end of the expansion, the value of $item is restored + to what it was before. + + * ${reduce{}{}{}} + + The ${reduce expansion operation reduces a list to a single, scalar string. + After expansion, is interpreted as a list, colon-separated by + default, but the separator can be changed in the usual way. Then + is expanded and assigned to the $value variable. After this, each item in + the list is assigned to $item in turn, and is expanded + for each of them. The result of that expansion is assigned to $value before + the next iteration. When the end of the list is reached, the final value of + $value is added to the expansion string. The ${reduce expansion item can be + used in a number of ways. For example, to add up a list of numbers: + + ${reduce {<, 1,2,3}{0}{${eval:$value+$item}}} + + The result of that expansion would be "6". The maximum of a list of numbers + can be found: + + ${reduce {3:0:9:4:6}{0}{${if >{$item}{$value}{$item}{$value}}}} + + At the end of a ${reduce expansion, the values of $item and $value is + restored to what they were before. + +17. There's a new ACL modifier called "continue". It does nothing of itself, + and processing of the ACL always continues with the next condition or + modifier. It is provided so that the side effects of expanding its argument + can be used. Typically this would be for updating a database. It is really + just a syntactic tidiness, because the following two lines have the same + effect: + + continue = + condition = ${if eq{0}{}{true}{true}} + +18. It is now possible to use newline and other control characters (those with + values less than 32, plus DEL) as separators in lists. Such separators must + be provided literally at the time the list is processed, but the string + expansion that happens first means that you can write them using normal + escape sequences. For example, if a new-line separated list of domains is + generated by a lookup, you can now process it directly by a line such as + this: + + domains = <\n ${lookup mysql{.....}} + + This avoids having to change the list separator in such data. Unlike + printing character separators, which can be included in list items by + doubling, it is not possible to include a control character as data when it + is set as the separator. Two such characters in succession are interpreted + as enclosing an empty list item. + +19. The exigrep utility now has a -v option, which inverts the matching + condition. + +20. The host_find_failed option in the manualroute router can now be set to + "ignore". This causes it to completely ignore a host whose IP address + cannot be found. If all the hosts in the list are ignored, the behaviour is + controlled by the new host_all_ignored option, which takes the same values + as host_find_failed, except that it cannot be set to "ignore". Its default + is "defer". + Version 4.66 ------------