Subversion Repositories planix.SVN

Rev

Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
2 - 1 
.TH REWRITE 6
2 
.SH NAME
3 
rewrite \- mail rewrite rules
4 
.SH SYNOPSIS
5 
.B /mail/lib/rewrite
6 
.SH DESCRIPTION
7 
.IR Mail (1)
8 
uses rewrite rules to convert mail destinations into
9 
commands used to dispose of the mail.
10 
Each line of the file
11 
.F /mail/lib/rewrite
12 
is a rule.
13 
Blank lines and lines beginning with
14 
.B #
15 
are ignored.
16 
.PP
17 
Each rewriting rule consists of (up to) 4 strings:
18 
.TF pattern
19 
.TP
20 
.I pattern
21 
A regular expression in the style of
22 
.IR regexp (6).
23 
The
24 
.I pattern
25 
is applied to mail destination addresses.
26 
The pattern match is case-insensitive
27 
and must match the entire address.
28 
.TP
29 
.I type
30 
The type of rule; see below.
31 
.TP
32 
.I arg1
33 
An
34 
.IR ed (1)
35 
style replacement string, with
36 
.BI \e n
37 
standing for the text matched by the
38 
.IR n th
39 
parenthesized subpattern.
40 
.TP
41 
.I arg2
42 
Another
43 
.IR ed (1)
44 
style replacement string.
45 
.PD
46 
.PP
47 
In each of these fields the substring
48 
.B \es
49 
is replaced by the login id of the
50 
sender and the substring
51 
.B \el
52 
is replaced by the name of the local machine.
53 
.PP
54 
When delivering a message,
55 
.I mail
56 
starts with the first rule and continues down the list until a pattern
57 
matches the destination address.
58 
It then performs one of the following actions depending on the
59 
.I type
60 
of the rule:
61 
.TF alias
62 
.TP
63 
.B >>
64 
Append the mail to the file indicated by expanding
65 
.IR arg1 ,
66 
provided that file appears to be a valid mailbox.
67 
.TP
68 
.B |
69 
Pipe the mail through the command formed from concatenating the
70 
expanded
71 
.I arg1
72 
and
73 
.IR arg2 .
74 
.TP
75 
.B alias
76 
Replace the address by the address(es) specified
77 
by expanding
78 
.I arg1
79 
and recur.
80 
.TP
81 
.B translate
82 
Replace the address by the address(es) output by the
83 
command formed by expanding
84 
.I arg1
85 
and recur.
86 
.PD
87 
.PP
88 
.I Mail
89 
expands the addresses recursively until each address has matched a
90 
.B >>
91 
or
92 
.B |
93 
rule or until the recursion depth indicates a rewriting loop
94 
(currently 32).
95 
.PD
96 
.PP
97 
If
98 
.IR mail (1)
99 
is called with more than one address and
100 
several addresses match
101 
.B |
102 
rules and result in the same
103 
expanded
104 
.IR arg1 ,
105 
the message is delivered to all those addresses
106 
by a single command,
107 
composed by concatenating the common expanded
108 
.I arg1
109 
and each expanded
110 
.IR arg2 .
111 
This mail bundling is performed to reduce the number
112 
of times the same message is transmitted across a
113 
network.  For example, with the following
114 
rewrite rule
115 
.PP
116 
.EX
117 
   ([^!]*\.bell-labs\.com)!(.*)  |  "/mail/lib/qmail '\es' 'net!\e1'" "'\e2'"
118 
.EE
119 
.PP
120 
if user
121 
.B presotto
122 
runs the command
123 
.PP
124 
.EX
125 
   % mail plan9.bell-labs.com!ken plan9.bell-labs.com!rob
126 
.EE
127 
.PP
128 
there will follow only one execution of the command
129 
.PP
130 
.EX
131 
   /mail/lib/qmail presotto net!plan9.bell-labs.com ken rob
132 
.EE
133 
.PP
134 
Here
135 
.B /mail/lib/qmail
136 
is an
137 
.IR rc (1)
138 
script used for locally queuing remote mail.
139 
.PP
140 
In the event of an error, the disposition of the mail depends on the name of the
141 
command executing the rewrite.  If the command is called
142 
.B mail
143 
and is run by
144 
.BR $user ,
145 
the command will print an error and deposit the message in
146 
.BR /mail/box/$user/dead.letter .
147 
If the command is called
148 
.BR rmail ,
149 
usually because it was invoked to deliver mail arriving over the network,
150 
the message will be returned to the sender.  The returned message will
151 
appear to have been sent by user
152 
.BR postmaster .
153 
.SH "SEE ALSO"
154 
.IR mail (1)