4 .TH MHSHOW %manext1% "%nmhdate%" MH.6.8 [%nmhversion%]
6 mhshow \- display MIME messages
29 command display contents of a MIME (multi-media)
30 message or collection of messages.
33 manipulates multi-media messages as specified in
34 RFC\-2045 thru RFC\-2049. Currently
37 encodings in message bodies, and does not support the encoding of
38 message headers as specified in RFC\-2047.
42 will display all parts of a multipart
50 to particular subparts (of a
51 multipart content) and/or particular content types.
58 to use the specified file as
59 the source message, rather than a message from a folder. If you specify
60 this file as \*(lq-\*(rq, then
62 will accept the source message
63 on the standard input. Note that the file, or input from standard input
64 should be a validly formatted message, just like any other
68 be in mail drop format (to convert a file in
69 mail drop format to a folder of
74 A part specification consists of a series of numbers separated by dots.
75 For example, in a multipart content containing three parts, these
76 would be named as 1, 2, and 3, respectively. If part 2 was also a
77 multipart content containing two parts, these would be named as 2.1 and
78 2.2, respectively. Note that the
80 switch is effective for only
81 messages containing a multipart content. If a message has some other
82 kind of content, or if the part is itself another multipart content, the
84 switch will not prevent the content from being acted upon.
86 A content specification consists of a content type and a subtype.
87 The initial list of \*(lqstandard\*(rq content types and subtypes can
88 be found in RFC\-2046.
90 A list of commonly used contents is briefly reproduced here:
98 multipart mixed, alternative, digest, parallel
99 message rfc822, partial, external-body
100 application octet-stream, postscript
107 A legal MIME message must contain a subtype specification.
109 To specify a content, regardless of its subtype, just use the
110 name of the content, e.g., \*(lqaudio\*(rq. To specify a specific
111 subtype, separate the two with a slash, e.g., \*(lqaudio/basic\*(rq.
112 Note that regardless of the values given to the `\-type' switch, a
113 multipart content (of any subtype listed above) is always acted upon.
114 Further note that if the `\-type' switch is used, and it is desirable to
115 act on a message/external-body content, then the `\-type' switch must
116 be used twice: once for message/external-body and once for the content
117 externally referenced.
118 .SS "Unseen Sequence"
119 If the profile entry \*(lqUnseen\-Sequence\*(rq is present and
122 will remove each of the messages shown
123 from each sequence named by the profile entry.
124 .SS "Showing the Contents"
125 The headers of each message are displayed with
127 using the standard format file
129 You may specify an alternate format file with the
132 switch. If the format file
134 is specified, then the display
135 of the message headers is suppressed.
137 Next, the contents are extracted from the message and are stored in
138 a temporary file. Usually, the name of the temporary file is the
139 word \*(lqmhshow\*(rq followed by a string of characters. Occasionally,
140 the method used to display a content (described next), requires that
141 the file end in a specific suffix. For example, the
143 command (part of the StarOffice package) can be used to display
144 Microsoft Word content, but it uses the suffix to determine how to display
145 the file. If no suffix is present, the file is not correctly loaded.
146 Similarily, older versions of the
148 command append a \*(lq.ps\*(rq suffix to
149 the filename if one was missing. As a result, these cannot be used to read
150 the default temporary file.
152 To get around this, your profile can contain lines of the form:
155 mhshow-suffix-<type>/<subtype>: <suffix>
161 mhshow-suffix-<type>: <suffix>
164 to specify a suffix which can be automatically added to the temporary
165 file created for a specific content type. For example, the following
166 lines might appear in your profile:
170 mhshow-suffix-text: .txt
171 mhshow-suffix-application/msword: .doc
172 mhshow-suffix-application/PostScript: .ps
176 to automatically append a suffix to the temporary files.
178 The method used to display the different contents in the messages bodies
179 will be determined by a \*(lqdisplay string\*(rq. To find the display
182 will first search your profile for an entry of the form:
185 mhshow-show-<type>/<subtype>
188 to determine the display string. If this isn't found,
190 will search for an entry of the form:
196 to determine the display string.
198 If a display string is found, any escapes (given below) will be expanded.
199 The result will be executed under
200 \*(lq/bin/sh\*(rq, with the standard input
203 The display string may contain the following escapes:
208 %a Insert parameters from Content-Type field
209 %e exclusive execution
210 %f Insert filename containing content
211 %F %e, %f, and stdin is terminal not content
212 %l display listing prior to displaying content
214 %s Insert content subtype
215 %d Insert content description
216 %% Insert the character %
220 For those display strings containing the e- or F-escape,
223 execute at most one of these at any given time. Although the F-escape
224 expands to be the filename containing the content, the e-escape has no
225 expansion as far as the shell is concerned.
229 is display a content, typing QUIT (usually
230 control-\\) will tell
232 to wrap things up immediately.
234 Note that if the content being displayed is multipart, but not one of
235 the subtypes listed above, then the f- and F-escapes expand to multiple
236 filenames, one for each subordinate content. Further, stdin is not
237 redirected from the terminal to the content.
239 If a display string is not found,
241 has the following default values:
245 mhshow-show-text/plain: %l<defaultpager> '%F'
246 mhshow-show-message/rfc822: %lshow \-file '%F'
250 If a subtype of type text doesn't have a profile entry, it will be
251 treated as text/plain.
254 has default methods for handling multipart messages of subtype
255 mixed, alternative, parallel, and digest. Any unknown subtype of type
256 multipart (without a profile entry), will be treated as multipart/mixed.
258 If none of these apply, then
260 will check to see if the message
261 has an application/octet-stream content with parameter \*(lqtype=tar\*(rq.
264 will use an appropriate command. If not,
268 Example entries might be:
272 mhshow-show-audio/basic: raw2audio 2>/dev/null | play
273 mhshow-show-image: xv '%f'
274 mhshow-show-application/PostScript: lpr -Pps
278 Note that when using the f- or F-escape, it's a good idea to use
279 single-quotes around the escape. This prevents misinterpretation by
280 the shell of any funny characters that might be present in the filename.
284 will process each message serially \- it won't start
285 showing the next message until all the commands executed to display the
286 current message have terminated. In the case of a multipart content
287 (of any subtype listed above), the content contains advice indicating if
288 the parts should be displayed serially or in parallel. Because this may
289 cause confusion, particularly on uni-window displays,
291 will never display parts in parallel.
292 .SS "Showing Alternate Character Sets"
293 Because a content of type text might be in a non-ASCII character
296 encounters a \*(lqcharset\*(rq parameter for
297 this content, it checks if your terminal can display this character
300 checks this by examining the the environment
303 If the value of this environment variable is equal
304 to the value of the charset parameter, then
307 display this content without any additional setup. If this environment
310 will assume a value of \*(lqUS-ASCII\*(rq.
311 If the character set cannot be displayed natively, then
313 will look for an entry of the form:
316 mhshow-charset-<charset>
319 which should contain a command creating an environment to render
320 the character set. This command string should containing a single
321 \*(lq%s\*(rq, which will be filled-in with the command to display the
324 Example entries might be:
327 mhshow-charset-iso-8859-1: xterm -fn '-*-*-medium-r-normal-*-*-120-*-*-c-*-iso8859-*' -e %s
333 mhshow-charset-iso-8859-1: '%s'
336 The first example tells
341 appropriate character set for that message content. The second example
344 that your pager (or other program handling that content
345 type) can handle that character set, and that no special processing is
348 Note that many pagers strip off the high-order bit or have problems
349 displaying text with the high-order bit set. However, the pager
351 has support for single-octet character sets. The source
354 is available on many ftp sites carrying free software.
355 In order to view messages sent in the ISO-8859-1 character set using
358 put these lines in your
364 setenv LESSCHARSET latin1
371 to use the ISO-8859-1 definition for
372 determining whether a character is \*(lqnormal\*(rq, \*(lqcontrol\*(lq,
373 or \*(lqbinary\*(rq. The second line tells
376 if it encounters a file that has non-ASCII characters. Then,
382 called automatically. (To handle other single-octet character sets,
385 manual entry for information about the
387 environment variable.)
388 .SS "Messages of Type message/partial"
390 cannot directly display messages of type partial.
391 You must reassemble them first into a normal message using
393 Check the man page for
396 .SS "External Access"
397 For contents of type message/external-body,
399 supports these access-types:
412 For the \*(lqanon-ftp\*(rq and \*(lqftp\*(rq access types,
414 will look for the \*(lqnmh-access-ftp\*(rq
418 nmh-access-ftp: myftp.sh
421 to determine the pathname of a program to perform the FTP retrieval.
423 This program is invoked with these arguments:
427 domain name of FTP-site
433 \*(lqascii\*(rq or \*(lqbinary\*(rq
437 The program should terminate with an exit status of zero if the
438 retrieval is successful, and a non-zero exit status otherwise.
439 .SS "User Environment"
440 Because the display environment in which
442 operates may vary for
445 will look for the environment variable
447 If present, this specifies the name of an additional
448 user profile which should be read. Hence, when a user logs in on a
449 particular display device, this environment variable should be set to
450 refer to a file containing definitions useful for the given display device.
451 Normally, only entries that deal with the methods to display different
452 content type and subtypes
456 mhshow-show-<type>/<subtype>
461 need be present in this additional profile. Finally,
463 will attempt to consult one other additional user profile,
467 %etcdir%/mhn.defaults
470 which is created automatically during
477 .ta \w'%etcdir%/ExtraBigFileName 'u
478 ^$HOME/.mmh/profile~^The user profile
479 ^$MHSHOW~^Additional profile entries
480 ^%etcdir%/mhn.defaults~^System default MIME profile entries
481 ^%etcdir%/mhl.headers~^The headers template
484 .SH "PROFILE COMPONENTS"
488 .ta \w'ExtraBigProfileName 'u
489 ^Path:~^To determine the user's mail storage
490 ^Current\-Folder:~^To find the default current folder
491 ^Unseen\-Sequence:~^To name sequences denoting unseen messages
492 ^nmh-access-ftp:~^Program to retrieve contents via FTP
493 ^mhshow-charset-<charset>~^Template for environment to render character sets
494 ^mhshow-show-<type>*~^Template for displaying contents
495 ^Pager:~^Default program to display text/plain content
499 mhbuild(1), mhl(1), mhlist(1), mhstore(1), sendfiles(1)
503 .RB ` +folder "' defaults to the current folder"
504 .RB ` msgs "' defaults to cur"
505 .RB ` \-form \ mhl.headers'
510 If a folder is given, it will become the current folder. The last
511 message selected will become the current message.
projects / mmh / blob