new.c: Order two return statements to match comment.

[nmh] / man / mhshow.man

diff --git a/man/mhshow.man b/man/mhshow.man
index 3f5bb94366e9106532f7f916865c4e68fbb5bd56..b53b55e66eb5b2f6e4b1cfabc0135ef91995f922 100644 (file)
--- a/man/mhshow.man
+++ b/man/mhshow.man
@@ -1,71 +1,177 @@
-.\"
+.TH MHSHOW %manext1% 2015-02-08 "%nmhversion%"
+.

 .\" %nmhwarning%
 .\" %nmhwarning%

-.\" $Id$
-.\"
-.\" include the -mh macro file
-.so %etcdir%/tmac.h
-.\"
-.TH MHSHOW %manext1% "%nmhdate%" MH.6.8 [%nmhversion%]
+.

 .SH NAME
 .SH NAME

-mhshow \- display MIME messages
+mhshow \- display nmh MIME messages

 .SH SYNOPSIS
 .SH SYNOPSIS

-.in +.5i
-.ti -.5i
-mhshow \%[+folder] \%[msgs] \%[\-file file]
-.br
-\%[\-part number]... \%[\-type content]...
-.br
-\%[\-serialonly] \%[\-noserialonly]
-\%[\-pause] \%[\-nopause]
-.br
-\%[\-check] \%[\-nocheck]
-\%[\-form formfile]
-.br
-\%[\-rcache policy] \%[\-wcache policy]
-.br
-\%[\-verbose] \%[\-noverbose]
-\%[\-version] \%[\-help]
-.in -.5i
-
+.HP 5
+.na
+.B mhshow
+.RB [ \-help ]
+.RB [ \-version ]
+.RI [ +folder ]
+.RI [ msgs ]
+.RB [ \-file
+.IR file ]
+.RB [ \-part
+.IR number ]
+\&...
+.RB [ \-type
+.IR content ]
+\&...
+.RB [ \-prefer
+.IR content ]
+\&...
+.RB [ \-noprefer ]
+.RB [ \-concat " | " \-noconcat ]
+.RB [ \-textonly " | " \-notextonly ]
+.RB [ \-inlineonly " | " \-noinlineonly ]
+.RB [ \-header " | " \-noheader ]
+.RB [ \-form
+.IR formfile ]
+.RB [ \-markform
+.IR formfile ]
+.RB [ \-rcache
+.IR policy ]
+.RB [ \-wcache
+.IR policy ]
+.RB [ \-check " | " \-nocheck ]
+.ad

 .SH DESCRIPTION
 .SH DESCRIPTION

-The \fImhshow\fR command display contents of a MIME (multi-media)
-message or collection of messages.
-
-\fImhshow\fR manipulates multi-media messages as specified in
-RFC\-2045 thru RFC\-2049.  Currently \fImhshow\fR only supports
-encodings in message bodies, and does not support the encoding of
-message headers as specified in RFC\-2047.
-
-By default \fImhshow\fR will display all parts of a multipart
-message.  By using the `\-part' and `\-type' switches, you may
-limit the scope of \fImhshow\fR to particular subparts (of a
-multipart content) and/or particular content types.
-
-The option `\-file\ file' directs \fImhshow\fR to use the specified file as
-the source message, rather than a message from a folder.  If you specify
-this file as \*(lq-\*(rq, then \fImhshow\fR will accept the source message
-on the standard input.  Note that the file, or input from standard input
-should be a validly formatted message, just like any other \fInmh\fR
-message.  It should \fBNOT\fR be in mail drop format (to convert a file in
-mail drop format to a folder of \fInmh\fR messages, see \fIinc\fR\0(1)).
-
+The
+.B mhshow
+command displays contents of a MIME (multi-media) message, or collection
+of messages.
+.PP
+.B mhshow
+manipulates multi-media messages as specified in RFC 2045 to RFC 2049.
+Currently
+.B mhshow
+only supports encodings in message bodies, and does not support the
+encoding of message headers as specified in RFC 2047.
+.PP
+By default,
+.B mhshow
+will display only the text parts of a message that are not marked as
+attachments.  This behavior can be changed by the
+.B \-notextonly
+and
+.B \-noinlineonly
+switches.
+In addition, by using the
+.BR \-part ,
+.BR \-type ,
+and
+.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
+switches will override the default settings of
+.B \-textonly
+and
+.BR \-inlineonly .
+.PP
+The
+.B \-header
+switch controls whether
+.B mhshow
+will print a message separator header before each message that it
+displays.  The header format can be controlled using
+.BR \-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 want each part to
+be displayed separately, you can override the default behavior with
+.B \-noconcat.
+.PP
+The
+.B \-file
+.I file
+switch directs
+.B mhshow
+to use the specified file as the source message, rather than a message
+from a folder.  If you specify this file as \*(lq-\*(rq, then
+.B mhshow
+will accept the source message on the standard input.  Note that the
+file, or input from standard input, should be a validly formatted message,
+just like any other
+.B nmh
+message.  It should
+.I not
+be in mail drop format (to convert a file in
+mail drop format to a folder of
+.B nmh
+messages, see
+.IR inc (1)).
+.PP
+The
+.B \-part
+switch can be given (one or more times) to restrict the set of
+subparts that will be displayed.  (Obviously with no
+.B \-part
+switches, all parts will be considered.)  If a
+.B \-part
+switch specifies a specific subpart (i.e., a "leaf" in the tree of
+MIME parts), then that part will always be displayed.  If a
+.B \-part
+switch references a multipart/alternative part, then (in
+the absence of a
+.B \-type
+switch) only the default subpart of that multipart will be displayed.
+.PP

 A part specification consists of a series of numbers separated by dots.
 For example, in a multipart content containing three parts, these
 would be named as 1, 2, and 3, respectively.  If part 2 was also a
 multipart content containing two parts, these would be named as 2.1 and
 A part specification consists of a series of numbers separated by dots.
 For example, in a multipart content containing three parts, these
 would be named as 1, 2, and 3, respectively.  If part 2 was also a
 multipart content containing two parts, these would be named as 2.1 and

-2.2, respectively.  Note that the `\-part' switch is effective for only
-messages containing a multipart content.  If a message has some other
-kind of content, or if the part is itself another multipart content, the
-`\-part' switch will not prevent the content from being acted upon.
-
+2.2, respectively.  Note that the
+.B \-part
+switch is effective only for messages containing a multipart content.
+If a message has some other kind of content, or if the part is itself
+another multipart content, the
+.B \-part
+switch will not prevent the content from being acted upon.
+.PP
+The
+.B \-type
+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
+.B \-type
+switches part will only select the first match 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 switch 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
 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.
-.ne 18
+be found in RFC 2046.
+.PP

 A list of commonly used contents is briefly reproduced here:
 A list of commonly used contents is briefly reproduced here:

-.sp
+.PP
+.RS 5

 .nf
 .nf

-.in +.5i

 .ta \w'application  'u
 Type   Subtypes
 ----   --------
 .ta \w'application  'u
 Type   Subtypes
 ----   --------


@@ -76,278 +182,396 @@ application      octet-stream, postscript
 image  jpeg, gif, png
 audio  basic
 video  mpeg
 image  jpeg, gif, png
 audio  basic
 video  mpeg

-.re
-.in -.5i

 .fi
 .fi

-.sp
+.RE
+.PP

 A legal MIME message must contain a subtype specification.
 .PP
 To specify a content, regardless of its subtype, just use the
 name of the content, e.g., \*(lqaudio\*(rq.  To specify a specific
 subtype, separate the two with a slash, e.g., \*(lqaudio/basic\*(rq.
 A legal MIME message must contain a subtype specification.
 .PP
 To specify a content, regardless of its subtype, just use the
 name of the content, e.g., \*(lqaudio\*(rq.  To specify a specific
 subtype, separate the two with a slash, e.g., \*(lqaudio/basic\*(rq.

-Note that regardless of the values given to the `\-type' switch, a
-multipart content (of any subtype listed above) is always acted upon.
-Further note that if the `\-type' switch is used, and it is desirable to
-act on a message/external-body content, then the `\-type' switch must
-be used twice: once for message/external-body and once for the content
-externally referenced.
-
-.Uh "Unseen Sequence"
-
+Note that regardless of the values given to the
+.B \-type
+switch, a multipart content (of any subtype listed above) is always
+acted upon.  Further note that if the
+.B \-type
+switch is used, and it is desirable to act on a message/external-body
+content, then the
+.B \-type
+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 ascending
+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.  Since the last of multiple 
+.B \-prefer
+options "wins", a
+.B \-prefer
+on the command line will override any in a profile entry.
+.PP
+The
+.B \-noprefer
+switch will cancel any previous
+.B \-prefer
+switches.
+.SS "Unseen Sequence"

 If the profile entry \*(lqUnseen\-Sequence\*(rq is present and
 If the profile entry \*(lqUnseen\-Sequence\*(rq is present and

-non\-empty, then \fImhshow\fR will remove each of the messages shown
-from each sequence named by the profile entry.
-
-.Uh "Checking the Contents"
-The `\-check' switch tells \fImhshow\fR to check each content for an
-integrity checksum.  If a content has such a checksum (specified as a
-Content-MD5 header field), then \fImhshow\fR will attempt to verify the
-integrity of the content.
-
-.Uh "Showing the Contents"
-The headers of each message are displayed with the \fImhlproc\fR
-(usually \fImhl\fR), using the standard format file \fImhl.headers\fR.
-You may specify an alternate format file with the `\-form formfile'
-switch.  If the format file \fImhl.null\fR is specified, then the display
-of the message headers is suppressed.
-
+non-empty, then
+.B mhshow
+will remove each of the messages shown from each sequence named by
+the profile entry.
+.SS "Checking the Contents"
+The
+.B \-check
+switch tells
+.B mhshow
+to check each content for an integrity checksum.  If a content has such
+a checksum (specified as a Content-MD5 header field), then
+.B mhshow
+will attempt to verify the integrity of the content.
+.SS "Showing the Contents"
+The headers of each message are displayed with the
+.I mhlproc
+(usually
+.BR mhl ),
+using the standard format file,
+.IR mhl.headers .
+You may specify an alternative format file with the
+.B \-form
+.I formfile
+switch.  If the format file
+.I mhl.null
+is specified, then the display of the message headers is suppressed.
+.PP

 Next, the contents are extracted from the message and are stored in
 Next, the contents are extracted from the message and are stored in

-a temporary file.  Usually, the name of the temporary file the
-word "mhshow" followed by a string of characters.  Occasionally,
+a temporary file.  Usually, the name of the temporary file is the
+word \*(lqmhshow\*(rq followed by a string of characters.  Occasionally,

 the method used to display a content (described next), requires that
 the method used to display a content (described next), requires that

-the file end in a specific suffix.  For example, the \fIsoffice\fR
+the file end in a specific suffix.  For example, the
+.B soffice

 command (part of the StarOffice package) can be used to display
 command (part of the StarOffice package) can be used to display

-MicroSoft Word content, but it uses the suffix to determine how 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.
 the file.  If no suffix is present, the file is not correctly loaded.

-Similarily, older versions of the \fIgs\fR command append a ".ps" suffix to
-the filename if one was missing.  As a result, these cannot be used to read
-the default temporary file.
-
+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 the default temporary file.
+.PP

 To get around this, your profile can contain lines of the form:
 To get around this, your profile can contain lines of the form:

-.sp
-.in +.5i
+.PP
+.RS 5

 mhshow-suffix-<type>/<subtype>: <suffix>
 mhshow-suffix-<type>/<subtype>: <suffix>

-.in -.5i
-.sp
+.RE
+.PP

 or
 or

-.sp
-.in +.5i
+.PP
+.RS 5

 mhshow-suffix-<type>: <suffix>
 mhshow-suffix-<type>: <suffix>

-.in -.5i
-.sp
+.RE
+.PP

 to specify a suffix which can be automatically added to the temporary
 file created for a specific content type.  For example, the following
 lines might appear in your profile:
 to specify a suffix which can be automatically added to the temporary
 file created for a specific content type.  For example, the following
 lines might appear in your profile:

-.sp
+.PP
+.RS 5

 .nf
 .nf

-.in +.5i

 mhshow-suffix-text: .txt
 mhshow-suffix-application/msword: .doc
 mhshow-suffix-application/PostScript: .ps
 mhshow-suffix-text: .txt
 mhshow-suffix-application/msword: .doc
 mhshow-suffix-application/PostScript: .ps

-.in -.5i

 .fi
 .fi

-.sp
+.RE
+.PP

 to automatically append a suffix to the temporary files.
 to automatically append a suffix to the temporary files.

-
+.PP

 The method used to display the different contents in the messages bodies
 will be determined by a \*(lqdisplay string\*(rq.  To find the display
 The method used to display the different contents in the messages bodies
 will be determined by a \*(lqdisplay string\*(rq.  To find the display

-string, \fImhshow\fR will first search your profile for an entry of the
-form:
-.sp
-.in +.5i
+string,
+.B mhshow
+will first search your profile for an entry of the form:
+.PP
+.RS 5

 mhshow-show-<type>/<subtype>
 mhshow-show-<type>/<subtype>

-.in -.5i
-.sp
-to determine the display string.  If this isn't found, \fImhshow\fR
+.RE
+.PP
+If this isn't found,
+.B mhshow

 will search for an entry of the form:
 will search for an entry of the form:

-.sp
-.in +.5i
+.PP
+.RS 5

 mhshow-show-<type>
 mhshow-show-<type>

-.in -.5i
-.sp
+.RE
+.PP

 to determine the display string.
 to determine the display string.

-
+.PP

 If a display string is found, any escapes (given below) will be expanded.
 If a display string is found, any escapes (given below) will be expanded.

-The result will be executed under \fB/bin/sh\fR, with the standard input
+The result will be executed under \*(lq/bin/sh\*(rq, with the standard input

 set to the content.
 set to the content.

-.ne 16
+.PP

 The display string may contain the following escapes:
 The display string may contain the following escapes:

-.sp
+.PP
+.RS 5

 .nf
 .nf

-.in +.5i
-.ta \w'%F  'u
-%a     Insert parameters from Content-Type field
-%e     exclusive execution
-%f     Insert filename containing content
-%F     %e, %f, and stdin is terminal not content
-%l     display listing prior to displaying content
-%p     %l, and ask for confirmation
-%s     Insert content subtype
-%d     Insert content description
-%%     Insert the character %
-.re
-.in -.5i
+.ta \w'%F        'u
+%a        Insert parameters from Content-Type field
+%{parameter} Insert the parameter value from the Content-Type field
+%f        Insert filename containing content
+%F        %f, and stdin is terminal not content
+%l        display listing prior to displaying content
+%s        Insert content subtype
+%d        Insert content description
+%%        Insert the character %

 .fi
 .fi

-.sp
-.ne 10
-For those display strings containing the e- or F-escape, \fImhshow\fR will
-execute at most one of these at any given time.  Although the F-escape
-expands to be the filename containing the content, the e-escape has no
-expansion as far as the shell is concerned.
-
-When the p-escape prompts for confirmation, typing INTR (usually
-control-C) will tell \fImhshow\fR not to display that content.
-The p-escape can be disabled by specifying the switch `\-nopause'.
-Further, when \fImhshow\fR is display a content, typing QUIT (usually
-control-\\) will tell \fImhshow\fR to wrap things up immediately.
-
+.RE
+.PP
+.B mhshow
+will execute at most one display string at any given time, and wait
+for the current display string to finish execution before executing
+the next display string.
+.PP
+The {parameter} escape is typically used in a command line argument
+that should only be present if it has a non-null value.  Its value
+will be wrapped with single quotes if the escape is not so wrapped.
+Shell parameter expansion can construct the argument only when it is
+non-null, e.g.,
+.PP
+.RS 5
+.nf
+mhshow-show-text/html: charset=%{charset};
+  w3m ${charset:+-I $charset} -T text/html %F
+.fi
+.RE
+.PP
+That example also shows the use of indentation to signify continuation:
+the two text lines combine to form a single entry.  Note that when
+dealing with text that has been converted internally by
+.IR iconv (3),
+the \*(lqcharset\*(rq parameter will reflect the target character set
+of the text, rather than the original character set in the message.
+.PP

 Note that if the content being displayed is multipart, but not one of
 the subtypes listed above, then the f- and F-escapes expand to multiple
 Note that if the content being displayed is multipart, but not one of
 the subtypes listed above, then the f- and F-escapes expand to multiple

-filenames, one for each subordinate content.  Further, stdin is not
+filenames, one for each subordinate content.  Furthermore, stdin is not

 redirected from the terminal to the content.
 redirected from the terminal to the content.

-
-If a display string is not found, \fImhshow\fR has several default values:
-.sp
+.PP
+If a display string is not found,
+.B mhshow
+behaves as if these profile entries were supplied and supported:
+.PP
+.RS 5

 .nf
 .nf

-.in +.5i
-mhshow-show-text/plain: %pmoreproc '%F'
-mhshow-show-message/rfc822: %pshow -file '%F'
-.in -.5i
+mhshow-show-text/plain: %lmoreproc %F
+mhshow-show-message/rfc822: %lshow -file %F

 .fi
 .fi

-.sp
+.RE
+.PP
+Note that \*(lqmoreproc\*(rq is not supported in user profile display
+strings.
+.PP

 If a subtype of type text doesn't have a profile entry, it will be
 treated as text/plain.
 If a subtype of type text doesn't have a profile entry, it will be
 treated as text/plain.

-
-\fImhshow\fR has default methods for handling multipart messages of subtype
+.PP
+.B mhshow
+has default methods for handling multipart messages of subtype

 mixed, alternative, parallel, and digest.  Any unknown subtype of type
 multipart (without a profile entry), will be treated as multipart/mixed.
 mixed, alternative, parallel, and digest.  Any unknown subtype of type
 multipart (without a profile entry), will be treated as multipart/mixed.

-
-If none of these apply, then \fImhshow\fR will check to see if the message
-has an application/octet-stream content with parameter \*(lqtype=tar\*(rq.
-If so, \fImhshow\fR will use an appropriate command.  If not, \fImhshow\fR
+.PP
+If none of these apply, then
+.B mhshow
+will check to see if the message has an application/octet-stream content
+with parameter \*(lqtype=tar\*(rq.
+If so,
+.B mhshow
+will use an appropriate command.  If not,
+.B mhshow

 will complain.
 will complain.

-
-.ne 10
+.PP

 Example entries might be:
 Example entries might be:

-.sp
+.PP
+.RS 5

 .nf
 .nf

-.in +.5i

 mhshow-show-audio/basic: raw2audio 2>/dev/null | play
 mhshow-show-audio/basic: raw2audio 2>/dev/null | play

-mhshow-show-image: xv '%f'
+mhshow-show-image: xv %f

 mhshow-show-application/PostScript: lpr -Pps
 mhshow-show-application/PostScript: lpr -Pps

-.in -.5i

 .fi
 .fi

-.sp
-Note that when using the f- or F-escape, it's a good idea to use
-single-quotes around the escape.  This prevents misinterpretation by
-the shell of any funny characters that might be present in the filename.
-
-Finally, \fImhshow\fR will process each message serially\0--\0it won't start
-showing the next message until all the commands executed to display the
-current message have terminated.  In the case of a multipart content
-(of any subtype listed above), the content contains advice indicating if
-the parts should be displayed serially or in parallel.  Because this may
-cause confusion, particularly on uni-window displays, the `\-serialonly'
-switch can be given to tell \fImhshow\fR to never display parts in parallel.
-
-.Uh "Showing Alternate Character Sets"
+.RE
+.PP
+If an f- or F-escape is not quoted with single quotes, its expansion
+will be wrapped with single quotes.
+.PP
+Finally,
+.B mhshow
+will process each message serially\0--\0it won't start showing the next
+message until all the commands executed to display the current message
+have terminated.
+.SS "Showing Alternate Character Sets"
+If
+.B mhshow
+was built with
+.IR iconv (3),
+then all text/plain parts of the message(s) will be displayed using
+the character set of the current locale.  See
+.IR mhparam (1)
+for how to determine whether your
+.B nmh
+installation includes
+.IR iconv (3)
+support.  To convert text parts other than text/plain, or if
+.B mhshow
+was not built with
+.IR iconv ,
+an external program can be used, as described next.
+.PP

 Because a content of type text might be in a non-ASCII character
 Because a content of type text might be in a non-ASCII character

-set, when \fImhshow\fR encounters a \*(lqcharset\*(rq parameter for
-this content, it checks if your terminal can display this character
-set natively.  \fIMhn\fR checks this by examining the the environment
-variable MM_CHARSET.  If the value of this environment variable is equal
-to the value of the charset parameter, then \fImhshow\fR assumes it can
-display this content without any additional setup.  If this environment
-variable is not set, \fImhshow\fR will assume a value of \*(lqUS-ASCII\*(rq.
-If the character set cannot be displayed natively, then \fImhshow\fR will
-look for an entry of the form:
-.sp
-.in +.5i
+set, when
+.B mhshow
+encounters a \*(lqcharset\*(rq parameter for this content, it checks
+if your terminal can display this character set natively.
+.B mhshow
+checks this by examining the current character set defined by the
+.IR locale (1)
+environment variables.  If the value of the locale character set is equal
+to the value of the charset parameter, then
+.B mhshow
+assumes it can
+display this content without any additional setup.  If the locale is not
+set properly,
+.B mhshow
+will assume a value of \*(lqUS-ASCII\*(rq.
+If the character set cannot be displayed natively, then
+.B mhshow
+will look for an entry of the form:
+.PP
+.RS 5

 mhshow-charset-<charset>
 mhshow-charset-<charset>

-.in -.5i
-.sp
+.RE
+.PP

 which should contain a command creating an environment to render
 the character set.  This command string should containing a single
 \*(lq%s\*(rq, which will be filled-in with the command to display the
 content.
 which should contain a command creating an environment to render
 the character set.  This command string should containing a single
 \*(lq%s\*(rq, which will be filled-in with the command to display the
 content.

-
+.PP

 Example entries might be:
 Example entries might be:

-.sp
-.in +.5i
+.PP
+.RS 5

 mhshow-charset-iso-8859-1: xterm -fn '-*-*-medium-r-normal-*-*-120-*-*-c-*-iso8859-*' -e %s
 mhshow-charset-iso-8859-1: xterm -fn '-*-*-medium-r-normal-*-*-120-*-*-c-*-iso8859-*' -e %s

-.in -.5i
+.RE
+.PP

 or
 or

-.in +.5i
+.PP
+.RS 5

 mhshow-charset-iso-8859-1: '%s'
 mhshow-charset-iso-8859-1: '%s'

-.in -.5i
-.sp
-The first example tells \fImhshow\fR to start \fIxterm\fR and load the
-appropriate character set for that message content.  The second example
-tells \fImhshow\fR that your pager (or other program handling that content
-type) can handle that character set, and that no special processing is
+.RE
+.PP
+The first example tells
+.B mhshow
+to start
+.B xterm
+and load the appropriate character set for that message content.
+The second example
+tells
+.B mhshow
+that your pager (or other program handling that content type) can
+handle that character set, and that no special processing is

 needed beforehand.
 needed beforehand.

-.sp
-Note that many pagers strip off the high-order bit or have problems
+.PP
+Note that many pagers strip off the high-order bit, or have problems

 displaying text with the high-order bit set.  However, the pager
 displaying text with the high-order bit set.  However, the pager

-\fIless\fR has support for single-octet character sets.  The source
-to \fIless\fR is available on many ftp sites carrying free software.
-In order to view messages sent in the ISO-8859-1 character set using
-\fIless\fR,
-.ne 9
-put these lines in your \&.login file:
-.sp
+.B less
+has support for single-octet character sets.  For example, messages
+encoded in the ISO-8859-1 character set can be viewed using
+.BR less ,
+with these environment variable settings:
+.PP
+.RS 5

 .nf
 .nf

-.in +.5i
-setenv LESSCHARSET latin1
-setenv LESS "-f"
-.in -.5i
+.ta \w'%F  'u
+LESSCHARSET latin1
+LESS        -f

 .fi
 .fi

-.sp
-The first line tells \fIless\fR to use the ISO-8859-1 definition for
-determining whether a character is \*(lqnormal\*(rq, \*(lqcontrol\*(lq,
-or \*(lqbinary\*(rq.  The second line tells \fIless\fR not to warn you
-if it encounters a file that has non-ASCII characters.  Then, simply
-set the \fBmoreproc\fR profile entry to \fIless\fR, and it will get
-called automatically.  (To handle other single-octet character sets,
-look at the \fIless\fR\0(1) manual entry for information about the
-\fBLESSCHARDEF\fR environment variable.)
-
-.Uh "Messages of Type message/partial"
-\fImhshow\fR cannot directly display messages of type partial.
-You must reassemble them first into a normal message using
-\fImhstore\fR.  Check the man page for \fImhstore\fR for details.
-
-.Uh "External Access"
+.RE
+.PP
+The first setting tells
+.B less
+to use the ISO-8859-1 definition to determine whether a character is
+\*(lqnormal\*(rq, \*(lqcontrol\*(lq, or \*(lqbinary\*(rq.
+The second setting tells
+.B less
+not to warn you if it encounters a file that has non-ASCII characters.
+Then, simply set the
+.I moreproc
+profile entry to
+.BR less ,
+and it will get called automatically.  (To handle other single-octet
+character sets, look at the
+.IR less (1)
+manual entry for information about the LESSCHARDEF environment variable.)
+.SS "Messages of Type message/partial"
+.B mhshow
+cannot directly display messages of type partial.
+You must first reassemble them into a normal message using
+.BR mhstore .
+Check
+.IR mhstore (1)
+for details.
+.SS "External Access"

 For contents of type message/external-body,
 For contents of type message/external-body,

-.ne 12
-\fImhshow\fR supports these access-types:
-.sp
-.nf
-.in +.5i
+.B mhshow
+supports these access-types:
+.IP \(bu 4

 afs
 afs

+.IP \(bu 4

 anon-ftp
 anon-ftp

+.IP \(bu 4

 ftp
 ftp

+.IP \(bu 4

 local-file
 local-file

+.IP \(bu 4

 mail-server
 mail-server

-.in -.5i
-.fi
-.sp
+.IP \(bu 4
+url
+.PP

 For the \*(lqanon-ftp\*(rq and \*(lqftp\*(rq access types,
 For the \*(lqanon-ftp\*(rq and \*(lqftp\*(rq access types,

-\fImhshow\fR will look for the \fBnmh-access-ftp\fR
-profile entry,
-.ne 6
-e.g.,
-.sp
-.in +.5i
+.B mhshow
+will look for the \*(lqnmh-access-ftp\*(rq profile entry, e.g.,
+.PP
+.RS 5

 nmh-access-ftp: myftp.sh
 nmh-access-ftp: myftp.sh

-.in -.5i
-.sp
+.RE
+.PP

 to determine the pathname of a program to perform the FTP retrieval.
 to determine the pathname of a program to perform the FTP retrieval.

-.ne 14
+.PP

 This program is invoked with these arguments:
 This program is invoked with these arguments:

-.sp
+.PP
+.RS 5

 .nf
 .nf

-.in +.5i

 domain name of FTP-site
 username
 password
 domain name of FTP-site
 username
 password


@@ -355,164 +579,196 @@ remote directory
 remote filename
 local filename
 \*(lqascii\*(rq or \*(lqbinary\*(rq
 remote filename
 local filename
 \*(lqascii\*(rq or \*(lqbinary\*(rq

-.in -.5i

 .fi
 .fi

-.sp
+.RE
+.PP

 The program should terminate with an exit status of zero if the
 retrieval is successful, and a non-zero exit status otherwise.
 The program should terminate with an exit status of zero if the
 retrieval is successful, and a non-zero exit status otherwise.

-
-If this entry is not provided, then \fImhshow\fR will use a simple
-built-in FTP client to perform the retrieval.
-
-.Uh "The Content Cache"
-When \fImhshow\fR encounters an external content containing a
-\*(lqContent-ID:\*(rq field, and if the content allows caching, then
-depending on the caching behavior of \fImhshow\fR, the content might be
-read from or written to a cache.
-
-The caching behavior of \fImhshow\fR is controlled with the `\-rcache'
-and `\-wcache' switches, which define the policy for reading from,
-and writing to, the cache, respectively.  One of four policies may be
-specified: \*(lqpublic\*(rq, indicating that \fImhshow\fR should make use
-of a publically-accessible content cache; \*(lqprivate\*(rq, indicating
-that \fImhshow\fR should make use of the user's private content cache;
-\*(lqnever\*(rq, indicating that \fImhshow\fR should never make use of
-caching; and, \*(lqask\*(rq, indicating that \fImhshow\fR should ask
-the user.
-
+.PP
+For the \*(lqurl\*(rq access-type,
+.B mhshow
+will look for the \*(lqnmh-access-url\*(rq profile entry.  See
+.IR mhstore (1)
+for more details.
+.SS "The Content Cache"
+When
+.B mhshow
+encounters an external content containing a \*(lqContent-ID:\*(rq field,
+and if the content allows caching, then depending on the caching behavior of
+.BR mhshow ,
+the content might be read from or written to a cache.
+.PP
+The caching behavior of
+.B mhshow
+is controlled with the
+.B \-rcache
+and
+.B \-wcache
+switches, which define the policy for reading from, and writing to, the cache,
+respectively.  One of four policies may be specified: \*(lqpublic\*(rq,
+indicating that
+.B mhshow
+should make use of a publicly-accessible content cache; \*(lqprivate\*(rq,
+indicating that
+.B mhshow
+should make use of the user's private content cache;
+\*(lqnever\*(rq, indicating that
+.B mhshow
+should never make use of caching; and, \*(lqask\*(rq, indicating that
+.B mhshow
+should ask the user.
+.PP

 There are two directories where contents may be cached: the profile entry
 There are two directories where contents may be cached: the profile entry

-\fBnmh-cache\fR names a directory containing world-readable contents, and,
-the profile entry \fBnmh-private-cache\fR names a directory containing
-private contents.  The former should be an absolute (rooted) directory
-name.
-.ne 6
+\*(lqnmh-cache\*(rq names a directory containing world-readable contents, and,
+the profile entry \*(lqnmh-private-cache\*(rq names a directory containing
+private contents.  The former should be an absolute (rooted) directory name.
+.PP

 For example,
 For example,

-.sp
-.in +.5i
+.PP
+.RS 5

 nmh-cache: /tmp
 nmh-cache: /tmp

-.in -.5i
-.sp
+.RE
+.PP

 might be used if you didn't care that the cache got wiped after each
 reboot of the system.  The latter is interpreted relative to the user's
 might be used if you didn't care that the cache got wiped after each
 reboot of the system.  The latter is interpreted relative to the user's

-nmh directory, if not rooted,
-.ne 6
-e.g.,
-.sp
-.in +.5i
+nmh directory, if not rooted, e.g.,
+.PP
+.RS 5

 nmh-private-cache: .cache
 nmh-private-cache: .cache

-.in -.5i
-.sp
+.RE
+.PP

 (which is the default value).
 (which is the default value).

-
-.Uh "User Environment"
-Because the display environment in which \fImhshow\fR operates may vary for
-different machines, \fImhshow\fR will look for the environment variable
-\fB$MHSHOW\fR.  If present, this specifies the name of an additional
-user profile which should be read.  Hence, when a user logs in on a
-particular display device, this environment variable should be set to
-refer to a file containing definitions useful for the given display device.
+.SS "User Environment"
+Because the display environment in which
+.B mhshow
+operates may vary for different machines,
+.B mhshow
+will look for the environment variable MHSHOW.  If present, this specifies
+the name of an additional user profile which should be read.
+Hence, when a user logs in on a particular display device, this environment
+variable should be set to refer to a file containing definitions useful
+for the given display device.

 Normally, only entries that deal with the methods to display different
 content type and subtypes
 Normally, only entries that deal with the methods to display different
 content type and subtypes

-.sp
-.in +.5i
+.PP
+.RS 5
+.nf

 mhshow-show-<type>/<subtype>
 mhshow-show-<type>/<subtype>

-.br

 mhshow-show-<type>
 mhshow-show-<type>

-.in -.5i
-.sp
-need be present in this additional profile.
-Finally,
-\fImhshow\fR will attempt to consult one other additional user profile,
-.ne 6
-e.g.,
-.sp
-.in +.5i
-%etcdir%/mhn.defaults
-.in -.5i
-.sp
-which is created automatically during nmh installation.
-.Fi
-^$HOME/\&.mh\(ruprofile~^The user profile
+.fi
+.RE
+.PP
+need be present in this additional profile.  Finally,
+.B mhshow
+will attempt to consult
+.PP
+.RS 5
+%nmhetcdir%/mhn.defaults
+.RE
+.PP
+which is created automatically during
+.B nmh
+installation.
+.PP
+See "Profile Lookup" in
+.IR mh-profile (5)
+for the profile search order, and for how duplicate entries are treated.
+.SS Content-Type Marker
+.B mhshow
+will display a marker containing information about the part being displayed
+next.  The default marker can be changed using the
+.B \-markform
+switch to specify a file containing
+.IR mh\-format (5)
+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
+escapes are supported:
+.PP
+.RS 5
+.nf
+.ta \w'cdispo-<PARAM>  'u +\w'Returns   'u
+.I "Escape     Returns Description"
+part   string  MIME part number
+content\-type  string  MIME Content\-Type of part
+description    string  Content\-Description header
+disposition    string  Content disposition (attachment or inline)
+ctype-<PARAM>  string  Value of <PARAM> from Content\-Type header
+cdispo-<PARAM> string  Value of <PARAM> from
+               Content\-Disposition header
+%(size)        integer The size of the decoded part, in bytes
+%(unseen)      boolean Returns true for suppressed parts
+.fi
+In this context, the %(unseen) function indicates whether
+.B mhshow
+has decided to not display a particular part due to the
+.B \-textonly
+or
+.B \-inlineonly
+switches.
+.RE
+All MIME parameters and the \*(lqContent-Description\*(rq header will have
+RFC 2231 decoding applied and be converted to the local character set.
+.SH FILES
+.B mhshow
+looks for all format files and mhn.defaults in multiple locations:
+absolute pathnames are accessed directly, tilde expansion is done on
+usernames, and files are searched for in the user's
+.I Mail
+directory, as specified in their profile.  If not found there, the directory
+.RI \*(lq %nmhetcdir% \*(rq
+is checked.
+.PP
+.fc ^ ~
+.nf
+.ta \w'%nmhetcdir%/ExtraBigFileName  'u
+^$HOME/.mh_profile~^The user profile

 ^$MHSHOW~^Additional profile entries
 ^$MHSHOW~^Additional profile entries

-^%etcdir%/mhn.defaults~^System default MIME profile entries
-^%etcdir%/mhl.headers~^The headers template
-.Pr
+^%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 ^ ~
+.nf
+.ta 2.4i
+.ta \w'ExtraBigProfileName  'u

 ^Path:~^To determine the user's nmh directory
 ^Path:~^To determine the user's nmh directory

-.Ps

 ^Current\-Folder:~^To find the default current folder
 ^Current\-Folder:~^To find the default current folder

-.Ps

 ^Unseen\-Sequence:~^To name sequences denoting unseen messages
 ^Unseen\-Sequence:~^To name sequences denoting unseen messages

-.Ps

 ^mhlproc:~^Default program to display message headers
 ^mhlproc:~^Default program to display message headers

-.Ps

 ^nmh-access-ftp:~^Program to retrieve contents via FTP
 ^nmh-access-ftp:~^Program to retrieve contents via FTP

-.Ps
+^nmh-access-url:~^Program to retrieve contents via HTTP

 ^nmh-cache~^Public directory to store cached external contents
 ^nmh-cache~^Public directory to store cached external contents

-.Ps

 ^nmh-private-cache~^Personal directory to store cached external contents
 ^nmh-private-cache~^Personal directory to store cached external contents

-.Ps

 ^mhshow-charset-<charset>~^Template for environment to render character sets
 ^mhshow-charset-<charset>~^Template for environment to render character sets

-.Ps

 ^mhshow-show-<type>*~^Template for displaying contents
 ^mhshow-show-<type>*~^Template for displaying contents

-.Ps

 ^moreproc:~^Default program to display text/plain content
 ^moreproc:~^Default program to display text/plain content

-.Sa
-mhbuild(1), mhl(1), mhlist(1), mhstore(1), sendfiles(1)
-.br
-RFC\-934:
-.br
-   \fIProposed Standard for Message Encapsulation\fR,
-.br
-RFC\-2045:
-.br
-   \fIMultipurpose Internet Mail Extensions (MIME) Part One:
-.br
-   Format of Internet Message Bodies\fR,
-.br
-RFC\-2046:
-.br
-   \fIMultipurpose Internet Mail Extensions (MIME) Part Two:
-.br
-   Media Types\fR,
-.br
-RFC\-2047:
-.br
-   \fIMultipurpose Internet Mail Extensions (MIME) Part Three:
-.br
-   Message Header Extensions for Non-ASCII Text\fR,
-.br
-RFC\-2048:
-.br
-   \fIMultipurpose Internet Mail Extensions (MIME) Part Four:
-.br
-   Registration Procedures\fR,
-.br
-RFC\-2049:
-.br
-   \fIMultipurpose Internet Mail Extensions (MIME) Part Five:
-.br
-   Conformance Criteria and Examples\fR.
-.De
-`+folder' defaults to the current folder
-.Ds
-`msgs' defaults to cur
-.Ds
-`\-nocheck'
-.Ds
-`\-form mhl.headers'
-.Ds
-`\-pause'
-.Ds
-`\-rcache ask'
-.Ds
-`\-realsize'
-.Ds
-`\-noserialonly'
-.Ds
-`\-noverbose'
-.Ds
-`\-wcache ask'
-.Co
+.fi
+.SH "SEE ALSO"
+.IR iconv (3),
+.IR mhbuild (1),
+.IR mhl (1),
+.IR mhlist (1),
+.IR mhparam (1),
+.IR mhstore (1),
+.IR sendfiles (1)
+.SH DEFAULTS
+.nf
+.RB ` +folder "' defaults to the current folder"
+.RB ` msgs "' defaults to cur"
+.RB ` \-nocheck '
+.RB ` \-concat '
+.RB ` \-textonly '
+.RB ` \-inlineonly '
+.RB ` \-form\ mhl.headers '
+.RB ` \-rcache\ ask '
+.RB ` \-wcache\ ask '
+.fi
+.SH CONTEXT

 If a folder is given, it will become the current folder.  The last
 message selected will become the current message.
 If a folder is given, it will become the current folder.  The last
 message selected will become the current message.

-.En