show.rf

早期freebsd实现

.\"	@(MHWARNING)
.\" @(#)$Id: show.rf,v 1.8 1993/10/26 20:09:07 jromine Exp $
.SC SHOW 1
.NA
show \- show (list) messages
.SY
show
\%[+folder] \%[msgs]
\%[\-draft]
\%[\-header] \%[\-noheader]
\%[\-showproc\ program] \%[\-noshowproc]
\%[switches\ for\ \fIshowproc\fR]
\%[\-help]
.DE
\fIShow\fR lists each of the specified messages to the standard
output (typically, the terminal).
Typically, the messages are listed exactly
as they are, with no reformatting.
A program named by the \fIshowproc\fR profile component is
invoked to do the listing, and any switches not recognized by
\fIshow\fR are passed along to that program.
The default program is known as \fImore\fR\0(1).
To override the default and the \fIshowproc\fR profile component,
use the `\-showproc\ program' switch.
For example, `\-show\ pr' will cause the \fIpr\fR\0(1) program to list the
messages.
The \fIMH\fR command \fImhl\fR can be used as a \fIshowproc\fR
to show messages in a more uniform format.
Normally, this program is specified as the \fIshowproc\fR is the user's
\&.mh\(ruprofile.
See \fImhl\fR\0(1) for the details.
If the `\-noshowproc' option is specified,
`/bin/cat' is used instead of \fIshowproc\fR.
@BEGIN: MIME

If you have messages with multi-media contents,
the profile entry \fImhnproc\fR defines the name of a program to
manipulate multi-media messages.
(The \fImhn\fR\0(1) program,
which is suitable for this purpose,
is the default.)
If the `\-noshowproc' option is NOT specified,
and if one or more named messages has a multi-media content,
then the program indicated by \fImhnproc\fR will be run instead of
\fIshowproc\fR.
The use of the \fImhnproc\fR can also be disabled if the
environment variable \fB$NOMHNPROC\fR is set.
Note that the \fImhnproc\fR may be invoked even for textual contents,
depending on the character set involved.
The environment variable $MM_CHARSET should be set to the terminal's
character set to avoid gratuitous invocations of the \fImhnproc\fR.
@END: MIME

The `\-header' switch tells \fIshow\fR 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.
If more than one message is specified,
\fImore\fR will prompt for a <RETURN> prior to listing each message.
\fImore\fR will list each message, a page at a time.
When the end of
page is reached, \fImore\fR will ring the bell and wait for a <SPACE>
or <RETURN>.
If a <RETURN> is entered, \fImore\fR will print the next line,
whereas <SPACE> will print the next screenful.
To exit \fImore\fR, type \*(lqq\*(rq.

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.

\*(lqshow \-draft\*(rq will list the file <mh\-dir>/draft if it
exists.

If the profile entry \*(lqUnseen\-Sequence\*(rq is present and non\-empty,
then \fIshow\fR will remove each of the messages shown from each
sequence named by the profile entry.
This is similar to the \*(lqPrevious\-Sequence\*(rq profile entry supported
by all \fIMH\fR commands which take `msgs' or `msg' arguments.
.Fi
^$HOME/\&.mh\(ruprofile~^The user profile
.Pr
^Path:~^To determine the user's MH directory
.Ps
^Current\-Folder:~^To find the default current folder
.Ps
^Unseen\-Sequence:~^To name sequences denoting unseen messages
.Ps
^showproc:~^Program to show messages
@BEGIN: MIME
.Ps
^mhnproc:~^Program to show messages with multi-media content
@END: MIME
.Sa
mhl(1), more(1), next(1), pick(1), prev(1), scan(1)
.De
`+folder' defaults to the current folder
.Ds
`msgs' defaults to cur
.Ds
`\-header'
.Co
If a folder is given, it will become the current folder.
The last message shown will become the current message.
.Bu
The `\-header' switch doesn't work when `msgs' expands to more than
one message.
If the \fIshowproc\fR is \fImhl\fR,
then is problem can be circumvented by referencing
the \*(lqmessagename\*(rq field in the \fImhl\fR format file.

\fIShow\fR updates the user's context before showing the message.
Hence \fIshow\fR 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 \fIshow\fR while it is showing \*(lqunseen\*(rq messages.

If \fIshowproc\fR is \fImhl\fR,
then \fIshow\fR uses a built\-in \fImhl\fR:
it does not actually run the \fImhl\fR program.
Hence, if you define your own \fIshowproc\fR,
don't call it \fImhl\fR since \fIshow\fR won't run it.

If \fImore\fR\0(1) is your showproc (the default),
then avoid running \fIshow\fR in the background
with only its standard output piped to another process, as in

.ti +.5i
show | imprint &

Due to a bug in \fImore\fR,
show will go into a \*(lqtty input\*(rq state.
To avoid this problem,
re\-direct \fIshow\fR's diagnostic output as well.
For users of \fIcsh\fR:

.ti +.5i
show |& imprint &

For users of \fIsh\fR:

.ti +.5i
show 2>&1 | imprint &
.En