uses a format file which directs it
how to generate the reply to a message, and so on.
.PP
-There are a few alternate scan listing formats available
-in
-.IR mmh/etc/scan.time ,
-.IR mmh/etc/scan.size ,
+There are a few alternate scan listing formats available, e.g.
+.IR scan.nmh ,
+.IR scan.mailx ,
and
-.IR mmh/etc/scan.timely .
+.IR scan.timely .
Look in
-.I mmh/etc
+.I %etcdir%
for other
.B scan
and
.B repl
-format files which may have been written at your site.
+format files.
.PP
-It suffices to have your local
-.B mh
-expert actually write new format
-commands or modify existing ones. This manual section explains how to
-do that. Note: familiarity with the C
+This manual section explains how to write and modify format commands.
+Note: familiarity with the C
.B printf
routine is assumed.
.PP
.SS SYNTAX
Format strings are built around
.IR "escape sequences" .
-There are three types of escape sequences: header
-.IR components ,
-built-in
-.IR functions ,
-and flow
-.IR control .
-Comments may be inserted in most places where a function argument is
-not expected. A comment begins with `%;' and ends with a (non-escaped)
+There are four types of escape sequences:
+.PP
+.RS 5
+.nf
+.ta +\w'name of escape class xxxxxxx'u
+.RI "1) header components %{" component }
+.RI "2) built-in functions %(" "function arg" )
+.RI "3) flow control %< ... %? ... %| ... %>
+.RI "4) comments %; ...
+.fi
+.RE
+.PP
+Comments may be inserted in most places where no function argument is
+expected. A comment begins with `%;' and ends with a (non-escaped)
newline.
.PP
A
or a control escape. When the argument is a function or a
component, they are listed without a leading `%'. When control escapes
are used as function arguments, they written as normally, with
-a leading `%';
+a leading `%'.
.SS "Control escapes"
.PP
.fi
.RE
.PP
-Extra white space is shown here only for clarity. These
+(Extra white space is shown here only for clarity.) These
constructs may be nested without ambiguity. They form a general
.B if\-elseif\-else\-endif
block where only one of the
a non-empty string, and false for an empty string.
.PP
-The `%?' control escape is optional, and may there may be more
+The `%?' control escape is optional, and there may be more
than one `%?' control escape in a conditional block.
The `%|' control escape
is also optional, but may be included at most once.
.\" compflag comp integer Set \fInum\fR to component flags bits (internal)
.\" decodecomp comp string Set \fIstr\fR to RFC-2047 decoded component text
decode expr string decode \fIstr\fR as RFC-2047 (MIME-encoded)
- component
+ component and print it
unquote expr string remove RFC-2822 quotes from \fIstr\fR
trim expr trim trailing white-space from \fIstr\fR
putstr expr print \fIstr\fR
dst date integer daylight savings in effect? (0 or 1)
clock date integer seconds since the UNIX epoch
rclock date integer seconds prior to current time
-tws date string official 822 rendering
+tws date string official RFC-822 rendering
pretty date string user-friendly rendering
.fi
.RE
.nf
.ta \w'Fformataddr 'u +\w'Aboolean 'u +\w'Rboolean 'u
.I "Function Argument Return Description
-proper addr string official 822 rendering
+proper addr string official RFC-822 rendering
friendly addr string user-friendly rendering
addr addr string mbox@host or host!mbox rendering*
pers addr string the personal name*
component in fourteen characters with trailing spaces added as needed.
For \fIputstrf\fR, using a negative value for the field width causes
right-justification of the string within the field, with padding on
-the left up to the field width.
-The functions (\fIputnum\fR\^) and
-(\fIputstr\fR\^) are somewhat special: they print their result in the minimum number of characters
-required, and ignore any leading field width argument.
+the left up to the field width. The functions (\fIputnum\fR\^) and
+(\fIputstr\fR\^) are somewhat special: they print their result in
+the minimum number of characters required, and ignore any leading
+field width argument.
.PP
The available output width is kept in an internal register; any output
past this width will be truncated.
.SS Examples
-With all this in mind,
-here's the default format string for
+With all this in mind, here's a format string for
.BR scan .
It's been divided into several pieces for readability.
The first part is:
.RE
.PP
This formats the
-`From:', `Sender:' and `Return-Path:'
+`From:', `Sender:' or `Return-Path:'
headers, stopping as soon as one of them is present. Next:
.PP
.RS 5
.PP
.RS 5
.nf
-%<{subject}Subject: Re: %{subject}\\n%>\\
+%<{subject}Subject: Re: %(decode{subject})\\n%>\\
.fi
.RE
.PP
.nf
.ta .5i 1i 1.5i 2i
if (comp_exists(message-id)) then
- print (`In-reply-to: ')
- print (message-id.value)
- print (`\\n')
+ print("In-reply-to: ")
+ print(message-id.value)
+ print("\\n")
endif
if (comp_exists(message-id)) then
- print (`References: ')
+ print("References: ")
if (comp_exists(references)) then
print(references.value);
endif
- print (message-id.value)
- print (`\\n')
+ print(message-id.value)
+ print("\\n")
endif
.fi
.RE
.\" (Note that this pseudocode begs the question ``why not just
.\" support this syntax?'' MH has been hacked on for a long time...)
.\".PP
-One more example: Currently,
-.B mmh
+One more example:
+.B Mmh
supports very
large message numbers, and it is not uncommon for a folder
to have far more than 10000 messages.
.\" process 200 messages a day and still get some real work
.\" done." The authors apparently only planned to get
.\" real work done for about 50 days per folder.)
-Nonetheless (as noted above)
-the various scan format strings are inherited
+Nonetheless several scan format strings are inherited
from older MH versions, and are generally hard-coded to 4
digits of message number before formatting problems
start to occur.
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