SHOW(1)
NAME
show - show (display) messages
SYNOPSIS
show [+folder] [msgs] [-showproc program]
[-showmimeproc program] [-header] [-noheader]
[-draft] [-checkmime] [-nocheckmime]
[switches for showproc or showmimeproc]
[-version] [-help]
DESCRIPTION
Show lists each of the specified messages to the standard
output (typically, the terminal).
By default, text (non-MIME) messages are filtered and dis-
played by the nmh command mhl. This command will display
text messages in a nice, uniform format. It also allows
you to configure the format of the displayed messages and
which headers fields are shown. See the mhl(1) manual
page for the details about this command. This default can
be changed by defining the showproc profile component.
Any switches not recognized by show are passed along to
that program. To override the default and the showproc
profile component, use the `-showproc program' switch.
For example, `-showproc more' will cause the more(1) pro-
gram to list the messages with no reformatting. Normally,
this program is specified as the showproc in the user's
.mh_profile, rather than using a command line switch.
By default, non-text messages (MIME messages with multi-
media contents) are processed and displayed by the nmh
command mhn. See the mhn(1) manual page for details about
this command. This default can changed by defining the
showmimeproc profile component. Any switches not recog-
nized by show are passed along to that program. To over-
ride this default and the showmimeproc profile component,
use the `-showmimeproc program' switch.
Note that in some cases, show may invoke the showmimeproc
even for textual contents. This will happen for text mes-
sages that specify a transfer encoding (such as MIME
quoted-printable or base64) or specify a character set
that show doesn't believe can be displayed natively. The
environment variable MM_CHARSET should be set to the ter-
minal's native character set to avoid gratuitous invoca-
tions of the showmimeproc. See the mh-profile (5) man
page for details about this environment variable.
The option `-checkmime' (set by default) instructs show to
test if any of the messages to be displayed are non-text
(MIME) messages. If any are non-text, they are displayed
by the program showmimeproc, else they are displayed by
the program showproc. The option `-nocheckmime' disables
this test and instructs show to use showproc, regardless
of whether any of the messages are non-text (MIME) mes-
sages.
The `-noshowproc' switch will disable any formatting or
paging of messages. It is equivalent to
`-nocheckmime -showproc cat'. It is still accepted, but
should be considered (somewhat) obsolete.
If the environment variable NOMHNPROC is set, the test for
non-text (MIME) messages will be disabled. This method is
obsolete. Use the `-nocheckmime' switch instead.
The `-header' switch tells show to display a one-line
description of the message being shown. This description
includes the folder and the message number.
If no `msgs' are specified, the current message is used.
Although it depends on the specific showproc or showmime-
proc, in the default setup when more than one message is
specified, you will be prompted for a <RETURN> prior to
listing each message. Each message will be listed a page
at a time, and when the end of page is reached, the pro-
gram will wait for a <SPACE> or <RETURN>. If a <RETURN>
is entered, it will print the next line, whereas <SPACE>
will print the next screenful.
If the standard output is not a terminal, no queries are
made, and each file is listed with a one-line header and
two lines of separation.
"show -draft" will list the file <mh-dir>/draft if it
exists.
If the profile entry "Unseen-Sequence" is present and
non-empty, then show will remove each of the messages
shown from each sequence named by the profile entry.
FILES
$HOME/.mh_profile The user profile
PROFILE COMPONENTS
Path: To determine the user's nmh directory
Current-Folder: To find the default current folder
Unseen-Sequence: To name sequences denoting unseen messages
showproc: Program to show text (non-MIME) messages
showmimeproc: Program to show non-text (MIME) messages
SEE ALSO
mhl(1) mhn(1) more(1) next(1) prev(1) scan(1)
DEFAULTS
`+folder' defaults to the current folder
`msgs' defaults to cur
`-checkmime'
`-header'
CONTEXT
If a folder is given, it will become the current folder.
The last message shown will become the current message.
BUGS
The `-header' switch doesn't work when `msgs' expands to
more than one message. If the showproc is mhl, then is
problem can be circumvented by referencing the "message-
name" field in the mhl format file.
Show updates the user's context before showing the mes-
sage. Hence show will mark messages as seen prior to the
user actually seeing them. This is generally not a prob-
lem, unless the user relies on the "unseen" messages mech-
anism, and interrupts show while it is showing "unseen"
messages.
If your showproc is mhl (the default), then show uses a
built-in mhl: it does not actually run the mhl program.
Hence, if you define your own showproc, don't call it mhl
since show won't run it.
If your showproc is the pager more, then avoid running
show in the background with only its standard output piped
to another process, as in
show | imprint &
Due to a bug in more, show will go into a "tty input"
state. To avoid this problem, re-direct show's diagnostic
output as well. For users of csh:
show |& imprint &
For users of sh:
show 2>&1 | imprint &