-.TH MHSHOW %manext1% "April 9, 2014" "%nmhversion%"
+.TH MHSHOW %manext1% "March 24, 2016" "%nmhversion%"
.\"
.\" %nmhwarning%
.\"
.HP 5
.na
.B mhshow
+.RB [ \-help ]
+.RB [ \-version ]
.RI [ +folder ]
.RI [ msgs ]
.RB [ \-file
.RB [ \-type
.IR content ]
\&...
+.RB [ \-prefer
+.IR content ]
+\&...
.RB [ \-concat " | " \-noconcat ]
.RB [ \-textonly " | " \-notextonly ]
.RB [ \-inlineonly " | " \-noinlineonly ]
+.RB [ \-header " | " \-noheader ]
.RB [ \-form
.IR formfile ]
.RB [ \-markform
.RB [ \-wcache
.IR policy ]
.RB [ \-check " | " \-nocheck ]
-.RB [ \-version ]
-.RB [ \-help ]
.ad
.SH DESCRIPTION
The
.B \-noinlineonly
switches.
In addition, by using the
-.B \-part
+.BR \-part ,
+.BR \-type ,
and
-.B \-type
-switches, you may
-further limit the scope of
-.B mhshow
-to particular subparts (of a
-multipart content) and/or particular content types. The inclusion of any
+.B \-prefer
+switches, you may limit and reorder the set of parts to be displayed,
+based on part number and/or content type.
+The inclusion of any
.B \-part
or
.B \-type
and
.BR \-inlineonly.
.PP
+The
+.B \-header
+switch control whether
+.B mhshow
+will print a message separator header before each message that it
+displays. The header format can be controlled using
+.B \-headerform
+to specify a file containing
+.IR mh\-format (5)
+instructions. A copy of the built-in default
+headerform can be found in %nmhetcdir%/mhshow.header, for reference.
+In addition to the normal set of
+.IR mh\-format (5)
+instructions, a "%{folder}" escape provides a
+string representing the current folder.
+.PP
By default
.B mhshow
-will concatenate all content under one pager. If you which each part to
+will concatenate all content under one pager. If you want each part to
displayed separately, you can override the default behavior with
.B \-noconcat.
.PP
.PP
The
.B \-type
-switch can also be used to restrict (or, when used in conjunction with
+switch can also be used to restrict (or, when used in conjunction with
.BR \-part ,
to further restrict) the display of parts according to content type.
One or more
from a multipart/alternative, even if there is more than one
subpart that matches (one of) the given content type(s).
.PP
+Using either
+.B \-part
+or
+.B -type
+switches alone will cause either to select
+the part(s) they match. Using them together will select only
+the part(s) matched by both (sets of) switches. In other
+words, the result is the intersection, and not the union, of their
+separate match results.
+.PP
A content specification consists of a content type and a subtype.
The initial list of \*(lqstandard\*(rq content types and subtypes can
be found in RFC 2046.
switch must
be used twice: once for message/external-body and once for the content
externally referenced.
+.PP
+In the absence of
+.BR \-prefer ,
+.B mhshow
+will select the "best" displayable subpart from
+multipart/alternative content. The
+.B \-prefer
+switch can be used (one or more times, in order of descending
+preference) to let MH know which content types from a
+multipart/alternative MIME part are preferred by the user, in order to
+override the default selection for display. For example, mail is
+often sent containing both plaintext and HTML-formatted versions of
+the same content, and the HTML version is usually indicated to be the
+"best" format for viewing. Using \*(lq-prefer text/plain\*(rq will
+cause the plaintext version to be displayed if possible, but still
+allow display of the HTML part if there is no plaintext subpart
+available. Using \*(lq-prefer text/plain -prefer image/png\*(rq
+would add a preference for PNG images, which might or might not
+ever appear in the same multipart/alternative section with text/plain.
+Implementation note: RFC 2046 requires that the subparts
+of a multipart/alternative be ordered according to "faithfulness to
+the original content", and MH by default selects the subpart ranked
+most "faithful" by that ordering. The
+.B \-prefer
+switch reorders the alternative parts (only internally, never changing
+the message file) to move the user's preferred part(s) to the "most
+faithful" position. Thus, when viewed by
+.BR mhlist ,
+the ordering of multipart/alternative parts will appear to change when
+invoked with or without various
+.B \-prefer
+switches.
.SS "Unseen Sequence"
If the profile entry \*(lqUnseen\-Sequence\*(rq is present and
non\-empty, then
command (part of the StarOffice package) can be used to display
Microsoft Word content, but it uses the suffix to determine how to display
the file. If no suffix is present, the file is not correctly loaded.
-Similarily, older versions of the
+Similarly, older versions of the
.B gs
command append a \*(lq.ps\*(rq suffix to
the filename if one was missing. As a result, these cannot be used to read
.IR iconv (3),
then all text/plain parts of the message(s) will be displayed using
the character set of the current locale. See the
-.BR mhparam (1)
+.IR mhparam (1)
man page for how determine whether your
.B nmh
installation includes
.fi
.RE
.PP
-need be present in this additional profile. Finally,
+need be present in this additional profile. Finally,
.B mhshow
will attempt to consult
.PP
.B \-markform
switch to specify a file containing
.IR mh\-format (5)
-instructions to use when displaying the content marker. In addition to
-the normal set of
+instructions to use when displaying the content marker. A copy of the
+default markform can be found in %nmhetcdir%/mhshow.marker, for
+reference. In addition to the normal set of
.IR mh\-format (5)
instructions, the following
.I component
^%nmhetcdir%/mhn.defaults~^System default MIME profile entries
^%nmhetcdir%/mhl.headers~^The headers template
^%nmhetcdir%/mhshow.marker~^Example content marker
+^%nmhetcdir%/mhshow.header~^Example message separator header
.fi
.SH "PROFILE COMPONENTS"
.fc ^ ~
projects / nmh / blobdiff