msh - nmh shell (and BBoard reader)

msh is an interactive program that implements a subset of the normal nmh commands operating on a single file in packf'dformat. That is, msh is used to read a file that contains a number of messages, as opposed to the standard nmh style of reading a number of files, each file being a separate message in a folder. msh's chief advantage is that the normal nmh style does not allow a file to have more than one message in it. Hence, msh is ideal for reading BBoards, as these files are delivered by the transport system in this format. In addition, msh can be used on other files, such as message archives which have been packed (see packf(1)). Finally, msh is an excellent nmh tutor. As the only commands available to the user are nmh commands, this allows nmh beginners to concentrate on how commands to nmh are formed and (more or less) what they mean.

When invoked, msh reads the named file, and enters a command loop. The user may type most of the normal nmh commands. The syntax and semantics of these commands typed to msh are identical to their nmh counterparts. In cases where the nature of msh would be inconsistent (e.g., specifying a +folder with some commands), msh will duly inform the user. The commands that msh currently supports (in some slightly modified or restricted forms) are:

ali
burst
comp
dist
folder
forw
inc
mark
mhmail
mhn
msgchk
next
packf
pick
prev
refile
repl
rmm
scan
send
show
sortm
whatnow
whom

In addition, msh has a help command which gives a brief overview. To terminate msh, type CTRL-D, or use the quit command. If msh is being invoked from bbc, then typing CTRL-D will also tell bbc to exit as well, while using the quit command will return control to bbc, and bbc will continue examining the list of BBoards that it is scanning.

If the file is writable and has been modified, then using quit will query the user if the file should be updated.

The -prompt string switch sets the prompting string for msh.

You may wish to use an alternate nmh profile for the commands that msh executes; see mh-profile(5) for details about the $MH environment variable.

When invoked from bbc, two special features are enabled: First, the -scan switch directs msh to do a “scan unseen” on start-up if new items are present in the BBoard. This feature is best used from bbc, which correctly sets the stage. Second, the mark command in msh acts specially when you are reading a BBoard, since msh will consult the sequence “unseen” in determining what messages you have actually read. When msh exits, it reports this information to bbc. In addition, if you give the mark command with no arguments, msh will interpret it as “mark -sequence unseen -delete -nozero all” Hence, to discard all of the messages in the current BBoard you're reading, just use the mark command with no arguments.

Normally, the exit command is identical to the quit command in msh. When run under bbc however, exit directs msh to mark all messages as seen and then quit. For speedy type-in, this command is often abbreviated as just qe.

When invoked from vmh, another special feature is enabled: The `topcur' switch directs msh to have the current message “track” the top line of the vmh scan window. Normally, msh has the current message “track” the center of the window (under -notopcur, which is the default).

msh supports an output redirection facility. Commands may be followed by one of

^> file~^write output to file
^>> file~^append output to file
^| command~^pipe output to UNIX command

If file starts with a “~” (tilde), then a csh-like expansion takes place. Note that command is interpreted by sh. Also note that msh does NOT support history substitutions, variable substitutions, or alias substitutions.

When parsing commands to the left of any redirection symbol, msh will honor `\' (back-slash) as the quote next-character symbol, and `“' (double-quote) as quote-word delimiters. All other input tokens are separated by whitespace (spaces and tabs).

^$HOME/.mhprofile~^The user profile
^/etc/nmh/mts.conf~^nmh mts configuration file

^Path:~^To determine the user's nmh directory
^Msg-Protect:~^To set mode when creating a new `file'
^fileproc:~^Program to file messages
^showproc:~^Program to show messages

bbc(1)

`file' defaults to “./msgbox”
`-prompt (msh) '
`-noscan'
`-notopcur'

None

The argument to the -prompt switch must be interpreted as a single token by the shell that invokes msh. Therefore, one must usually place the argument to this switch inside double-quotes.

There is a strict limit of messages per file in packf'd format which msh can handle. Usually, this limit is 1000 messages.

Please remember that msh is not the C-Shell, and that a lot of the nice facilities provided by the latter are not present in the former.

In particular, msh does not understand back-quoting, so the only effective way to use pick inside msh is to always use the -seq select switch. Clever users of nmh will put the line

pick:0-seq0select0-list

in their .mhprofile file so that pick works equally well from both the shell and msh.

sortm always uses -noverbose and if -textfield field is used, -limit 0.

The msh program inherits most (if not all) of the bugs from the nmh commands it implements.