.TH SHOW %manext1% 2016-03-24 "%nmhversion%"
.
.\" %nmhwarning%
.
.SH NAME
show \- display nmh messages
.SH SYNOPSIS
.HP 5
.na
.B show
.RB [ \-help ]
.RB [ \-version ]
.RI [ +folder ]
.RI [ msgs ]
.RB [ \-draft ]
.RB [ \-showproc
.IR program ]
.RB [ \-showmimeproc
.IR program ]
.RB [ \-header " | " \-noheader ]
.RB [ \-checkmime " | " \-nocheckmime ]
.RB [ \-concat " | " \-noconcat ]
[switches\ for
.I showproc
or
.IR showmimeproc ]
.ad
.SH DESCRIPTION
.B show
lists each of the specified messages to the standard output
(typically, the terminal).
.PP
By default, text (non-MIME) messages are filtered and displayed by
the
.B nmh
command
.BR 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
.IR mhl (1)
manual page for the details about this
command.  This default can be changed by defining the
.I showproc
profile component.  Any switches not recognized by
.BR show ,
as well as
.B \-header
and
.BR \-noheader ,
are
passed along to that program.  To override the default and the
.I showproc
profile component, use the
.B \-showproc
.I program
switch.  For example,
.B \-showproc
.I more
will cause the
.B more
program to list the messages with no reformatting.  Normally, this
program is specified as the
.I showproc
in the user's
.IR \&.mh_profile ,
rather than using a command line switch.
.PP
By default, non-text messages (MIME messages with multi-media
contents) are processed and displayed by the
.B nmh
command
.BR mhshow .
See the
.IR mhshow (1)
manual page for details
about this command.  This default can changed by defining the
.I showmimeproc
profile component.  Any switches not recognized
by
.B show
are passed along to that program.  To override this
default and the
.B showmimeproc
profile component, use the
.B \-showmimeproc
.I program
switch.
.PP
Note that in some cases,
.B show
may invoke the
.I showmimeproc
even for textual contents.  This will happen for text messages that
specify a transfer encoding (such as MIME quoted-printable or
base64) or specify a character set that
.B show
doesn't believe
can be displayed natively.  The appropriate
.IR locale (1)
environment variables
should be set to the terminal's native character set to avoid
gratuitous invocations of the
.IR showmimeproc .
See
.IR locale (1)
for details about these environment variables.
.PP
The option
.B \-checkmime
(set by default) instructs
.B 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
.IR showmimeproc ,
else they are displayed by the program
.IR showproc .
The option
.B \-nocheckmime
disables this test and instructs
.B show
to use
.IR showproc ,
regardless of whether
any of the messages are non-text (MIME) messages.
.P
The
.B \-noshowproc
switch will disable any formatting or paging of
messages.  It is equivalent to
.B \-nocheckmime
.B \-showproc
.IR cat .
It is still accepted, but should be considered (somewhat) obsolete.
.PP
The
.B \-header
switch tells
.B show
to display a one-line
description of the message being shown.  This description includes
the folder and the message number.
.PP
By default
.B show
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
If no `msgs' are specified, the current message is used.  Although
it depends on the specific
.I showproc
or
.IR showmimeproc ,
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 program 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.
.PP
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.
.PP
.RB \*(lq "show \-draft" \*(rq
will list the file <mh-dir>/draft if it
exists.
.PP
If the profile entry \*(lqUnseen\-Sequence\*(rq is present and
non-empty, then
.B show
will remove each of the messages shown
from each sequence named by the profile entry.
.SH FILES
.fc ^ ~
.nf
.ta \w'%nmhetcdir%/ExtraBigFileName  'u
^$HOME/.mh_profile~^The user profile
.fi
.SH "PROFILE COMPONENTS"
.fc ^ ~
.nf
.ta 2.4i
.ta \w'ExtraBigProfileName  'u
^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
.fi
.SH "SEE ALSO"
.IR mhl (1),
.IR mhshow (1),
.IR next (1),
.IR prev (1),
.IR scan (1)
.SH DEFAULTS
.nf
.RB ` +folder "' defaults to the current folder"
.RB ` msgs "' defaults to cur"
.RB ` \-checkmime '
.RB ` \-header '
.RB ` \-concat '
.fi
.SH CONTEXT
If a folder is given, it will become the current folder.  The last
message selected will become the current message.
.SH BUGS
The
.B \-header
switch doesn't work when `msgs' expands to more than
one message.  If the
.I showproc
is
.BR mhl ,
then this problem can
be circumvented by referencing the \*(lqmessagename\*(rq field in the
.B mhl
format file.
.PP
.B show
updates the user's context before showing the message.
Hence
.B show
will mark messages as seen prior to the user actually
seeing them.  This is generally not a problem, unless the user relies
on the \*(lqunseen\*(rq messages mechanism, and interrupts
.B show
while it is showing \*(lqunseen\*(rq messages.
.PP
If your
.I showproc
is
.B mhl
(the default), then
.B show
uses
a built-in
.BR mhl :
it does not actually run the
.B mhl
program.
Hence, if you define your own
.BR showproc ,
don't call it
.B mhl
since
.B show
won't run it.
.PP
If your
.I showproc
is the pager
.BR more ,
then avoid running
.B show
in the background with only its standard output piped to
another process, as in
.PP
.RS 5
show | imprint &
.RE
.PP
Due to a bug in
.BR more ,
show will go into a \*(lqtty input\*(rq state.
To avoid this problem, re-direct
.BR show 's
diagnostic output as well.
For users of
.BR csh :
.PP
.RS 5
show |& imprint &
.RE
.PP
For users of
.BR sh :
.PP
.RS 5
show 2>&1 | imprint &
.RE