.\"
-.\" THIS FILE HAS BEEN AUTOMATICALLY GENERATED. DO NOT EDIT.
-.\" $Id$
+.\" %nmhwarning%
.\"
.TH MH-FORMAT %manext5% "%nmhdate%" MH.6.8 [%nmhversion%]
.SH NAME
compressed by converting any control characters (tab and newline included)
to spaces, then eliding any leading or multiple spaces. However, commands
may give different interpretations to some component escapes; be sure
-to refer to each command's manual entry for complete details.
+to refer to each command's manual entry for complete details. Some commands
+(such as
+.B ap
+and
+.BR mhl )
+use a special component
+.RI `%{ text }'
+to refer to the text being processed; see their respective man pages for
+details and examples.
.PP
A
.I function
width integer output buffer size in bytes
charleft integer bytes left in output buffer
timenow integer seconds since the UNIX epoch
-me string the user's mailbox
+me string the user's mailbox (username)
+myhost string the user's local hostname
+myname string the user's name
+localmbox string the complete local mailbox
eq literal boolean \fInum\fR == \fIarg\fR
ne literal boolean \fInum\fR != \fIarg\fR
gt literal boolean \fInum\fR > \fIarg\fR
.\" decodecomp comp string Set \fIstr\fR to RFC-2047 decoded component text
decode expr string decode \fIstr\fR as RFC-2047 (MIME-encoded)
component
+unquote expr string remove RFC-2822 quotes from \fIstr\fR
trim expr trim trailing white-space from \fIstr\fR
putstr expr print \fIstr\fR
putstrf expr print \fIstr\fR in a fixed width
putnum expr print \fInum\fR
putnumf expr print \fInum\fR in a fixed width
.\" addtoseq literal add msg to sequence (LBL option)
+putlit expr print \fIstr\fR without space compression
nodate string integer Argument not a date string (0 or 1)
formataddr expr append \fIarg\fR to \fIstr\fR as a
(comma separated) address list
+concataddr expr append \fIarg\fR to \fIstr\fR as a
+ (comma separated) address list,
+ including duplicates,
+ see Special Handling
putaddr literal print \fIstr\fR address list with
\fIarg\fR as optional label;
get line width from \fInum\fR
.fi
.RE
.PP
+The (\fIme\fR\^) function returns the username of the current user. The
+(\fImyhost\fR\^) function returns the
+.B localname
+entry in
+.IR mts.conf ,
+or the local hostname if
+.B localname
+is not configured. The (\fImyname\fR\^) function will return the value of
+the
+.B SIGNATURE
+environment variable if set, otherwise will return the passwd GECOS field for
+the current user. The (\fIlocalmbox\fR\^) function will return the complete
+form of the local mailbox, suitable for use in a \*(lqFrom\*(rq header.
+It will return the
+.RI \*(lq Local-Mailbox \*(rq
+profile entry if it is set; if it is not, it will be equivalent to:
+.PP
+.RS 5
+.nf
+%(myname) <%(me)@%(myhost)>
+.fi
+.RE
+.PP
The following functions require a date component as an argument:
.PP
.RS 5
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.
+required, and ignore any leading field width argument. The (\fIputlit\fR\^)
+function outputs the exact contents of str register without any changes
+such as duplicate space removal or control character conversion.
.PP
The available output width is kept in an internal register; any output
past this width will be truncated.
+.SS Special Handling
+A few functions have different behavior depending on what command they are
+being invoked from.
+.PP
+In
+.BR repl
+the (\fIformataddr\fR\^) function stores all email addresses encountered into
+an internal cache and will use this cache to suppress duplicate addresses.
+If you need to create an address list that includes previously-seen
+addresses you may use the (\fIconcataddr\fR\^) function, which is identical
+to (\fIformataddr\fR\^) in all other respects. Note that (\fIconcataddr\fR\^)
+will NOT add addresses to the duplicate-suppression cache.
+.SS Other Hints and Tips
+Sometimes to format function writers it is confusing as to why output is
+duplicated. The general rule to remember is simple: If a function or
+component escape is used where it starts with a %, then it will generate
+text in the output file. Otherwise, it will not.
+.PP
+A good example is a simple attempt to generate a To: header based on
+the From: and Reply-To: headers:
+.PP
+.RS 5
+.nf
+%(formataddr %<{reply-to}%|%{from})%(putaddr To: )
+.fi
+.RE
+.PP
+Unfortuantely if the Reply-to: header is NOT present, the output line that is
+generated will be something like:
+.PP
+.RS 5
+.nf
+My From User <from@user.com>To: My From User <from@user.com>
+.fi
+.RE
+.PP
+What went wrong? When performing the test for the
+.B if
+clause (%<), the component is not output because it is considered an
+argument to the
+.B if
+statement (hence the rule about the lack of % applies). But the component
+escape in our
+.B else
+statement (everything after the `%|') is NOT an argument to anything; the
+syntax is that it is written with a %, and thus the value of that component
+is output. This also has the side effect of setting the
+.I str
+register, which is later picked up by the (\fIformataddr\fR\^) function
+and then output by (\fIputaddr\fR\^). This format string has another bug
+as well; there should always be a valid width value in the
+.I num
+register when (\fIputaddr\fR\^) is called, otherwise bad formatting can take
+place.
+.PP
+The solution is to use the (\fIvoid\fR\^) function; this will prevent the
+function or component from outputting any text. With this in place (and
+using (\fIwidth\fR\^) to set the
+.I num
+register for the width, a better implementation would look like:
+.PP
+.RS 3
+.nf
+%(formataddr %<{reply-to}%|%(void{from})%(void(width))%(putaddr To: )
+.fi
+.RE
+.PP
+It should be noted here that the side-effects of functions and component
+escapes still are in force: as a result each component
+test in the
+.B if\-elseif\-else\-endif
+clause sets the
+.I str
+register.
+.PP
+As an additional note, the (\fIformataddr\fR\^) and (\fIconcataddr\fR\^)
+functions have some behavior when it comes to the
+.I str
+register. The starting point of the register is saved and is used to
+build up entries in the address list.
+.PP
+You will find the
+.B ap
+and
+.B fmtdump
+utilities invaluable in debugging problems with format strings.
.SS Examples
With all this in mind,
here's the default format string for
.PP
.RS 5
.nf
-%<{date} %|*>
+%<{date} %|*%>
.fi
.RE
.PP
projects / mmh / blobdiff