mh-e: Viewing Attachments
6.2 Viewing Attachments
=======================
MH has the ability to display “MIME” (Multipurpose Internet Mail
Extensions) messages which are simply messages with additional “body
parts” or “attachments”. You can use the MH commands ‘show’(1) or
‘mhshow’(2) from the shell to read MIME messages(3).
MH-E can handle attachments as well if the Gnus ‘mm-decode’ package
is present. If so, the option ‘mh-decode-mime-flag’ will be on.
Otherwise, you’ll see the MIME body parts rather than text or
attachments. There isn’t much point in turning off the option
‘mh-decode-mime-flag’; however, you can inspect it if it appears that
the body parts are not being interpreted correctly or toggle it with the
command ‘;’ (semicolon; ‘mh-toggle-mh-decode-mime-flag’) to view the raw
message. This option also controls the display of quoted-printable
messages and other graphical widgets. 
Viewing.
Attachments in MH-E are indicated by “buttons” like this:
[1. image/jpeg; foo.jpg]...
To view the contents of the button, use either ‘mouse-1’ or ‘mouse-2’
on the button or <RET> (‘mh-press-button’) when the cursor is over the
button. This command is a toggle so if you use it again on the same
attachment, it is hidden. If Emacs does not know how to display the
attachment, then Emacs offers to save the attachment in a file. To move
the cursor to the next button, use the command ‘K <TAB>’
(‘mh-next-button’). If the end of the buffer is reached then the search
wraps over to the start of the buffer. To move the cursor to the
previous button, use the command ‘K S-<TAB>’ (‘mh-prev-button’). If the
beginning of the buffer is reached then the search wraps over to the end
of the buffer.
Another way to view the contents of a button is to use the command ‘K
v’ (‘mh-folder-toggle-mime-part’). This command displays (or hides) the
attachment associated with the button under the cursor. If the cursor
is not located over a button, then the cursor first moves to the next
button, wrapping to the beginning of the message if necessary. This
command has the advantage over the previous commands of working from the
MH-Folder buffer. You can also provide a numeric prefix argument (as in
‘4 K v’) to view the attachment labeled with that number. If Emacs does
not know how to display the attachment, then Emacs offers to save the
attachment in a file.
If Emacs does not know how to view an attachment, you could save it
into a file and then run some program to open it. It is easier,
however, to launch the program directly from MH-E with the command ‘K e’
(‘mh-display-with-external-viewer’). While you’ll most likely use this
to view spreadsheets and documents, it is also useful to use your
browser to view HTML attachments with higher fidelity than what Emacs
can provide. This command displays the attachment associated with the
button under the cursor. If the cursor is not located over a button,
then the cursor first moves to the next button, wrapping to the
beginning of the message if necessary. You can provide a numeric prefix
argument (as in ‘4 K e’) to view the attachment labeled with that
number. This command tries to provide a reasonable default for the
viewer by calling the Emacs function ‘mailcap-mime-info’. This function
usually reads the file ‘/etc/mailcap’.
Use the command ‘K o’ (‘mh-folder-save-mime-part’) to save
attachments (the mnemonic is “output”). This command saves the
attachment associated with the button under the cursor. If the cursor
is not located over a button, then the cursor first moves to the next
button, wrapping to the beginning of the message if necessary. You can
also provide a numeric prefix argument (as in ‘3 K o’) to save the
attachment labeled with that number. This command prompts you for a
filename and suggests a specific name if it is available.
You can save all of the attachments at once with the command ‘K a’
(‘mh-mime-save-parts’). The attachments are saved in the directory
specified by the option ‘mh-mime-save-parts-default-directory’ unless
you use a prefix argument (as in ‘C-u K a’) in which case you are
prompted for the directory. These directories may be superseded by MH
profile components, since this function calls on ‘mhstore’ (‘mhn’) to do
the work.
The default value for the option
‘mh-mime-save-parts-default-directory’ is ‘Prompt Always’ so that you
are always prompted for the directory in which to save the attachments.
However, if you usually use the same directory within a session, then
you can set this option to ‘Prompt the First Time’ to avoid the prompt
each time. you can make this directory permanent by choosing
‘Directory’ and entering the directory’s name.
The sender can request that attachments should be viewed inline so
that they do not really appear like an attachment at all to the reader.
Most of the time, this is desirable, so by default MH-E suppresses the
buttons for inline attachments. On the other hand, you may receive code
or HTML which the sender has added to his message as inline attachments
so that you can read them in MH-E. In this case, it is useful to see
the buttons so that you know you don’t have to cut and paste the code
into a file; you can simply save the attachment. If you want to make
the buttons visible for inline attachments, you can use the command ‘K
t’ (‘mh-toggle-mime-buttons’) to toggle the visibility of these buttons.
You can turn on these buttons permanently by turning on the option
‘mh-display-buttons-for-inline-parts-flag’.
MH-E cannot display all attachments inline however. It can display
text (including HTML) and images.
Some older mail programs do not insert the needed plumbing(4) to tell
MH-E whether to display the attachments inline or not. If this is the
case, MH-E will display these images inline if they are smaller than the
window. However, you might want to allow larger images to be displayed
inline. To do this, you can change the options
‘mh-max-inline-image-width’ and ‘mh-max-inline-image-height’ from their
default value of zero to a large number. The size of your screen is a
good choice for these numbers.
Sometimes, a mail program will produce multiple alternatives of an
attachment in increasing degree of faithfulness to the original content.
By default, only the preferred alternative is displayed. If the option
‘mh-display-buttons-for-alternatives-flag’ is on, then the preferred
part is shown inline and buttons are shown for each of the other
alternatives.
Many people prefer to see the ‘text/plain’ alternative rather than
the ‘text/html’ alternative. To do this in MH-E, customize the option
‘mm-discouraged-alternatives’, and add ‘text/html’. The next best
alternative, if any, will be shown.
Occasionally, though, you might want to see the preferred
alternative. The command ‘:’ (‘mh-show-preferred-alternative’) displays
the message with the default preferred alternative. This is as if
‘mm-discouraged-alternatives’ is set to ‘nil’. Use the command <RET>
(‘mh-show’) to show the message normally again.
You can view the raw contents of an attachment with the command ‘K i’
(‘mh-folder-inline-mime-part’). This command displays (or hides) the
contents of the attachment associated with the button under the cursor
verbatim. If the cursor is not located over a button, then the cursor
first moves to the next button, wrapping to the beginning of the message
if necessary. You can also provide a numeric prefix argument (as in ‘4
K i’) to view the attachment labeled with that number.
For additional information on buttons, see (gnus)Article
Buttons, and (gnus)MIME Commands.
---------- Footnotes ----------
(1) See the section Reading Mail: inc show next prev
(http://rand-mh.sourceforge.net/book/mh/reapre.html) in the MH book.
(2) See the section Reading MIME Mail
(http://rand-mh.sourceforge.net/book/mh/usimim.html#ReMIMa) in the MH
book.
(3) You can call them directly from Emacs if you’re running the X
Window System: type ‘M-! xterm -e mhshow MESSAGE-NUMBER’. You can leave
out the ‘xterm -e’ if you use ‘mhlist’ or ‘mhstore’.
(4) This plumbing is the ‘Content-Disposition:’ header field.
Info Catalog
mh-e: Viewing
mh-e: Reading Mail
mh-e: HTML