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mhl(1)								       mhl(1)



NAME

  mhl -	produce	formatted listings of MH messages (only	available within the
  message handling system, mh)

SYNOPSIS

  mhl [options]	[files...]

OPTIONS

  -bell

  -nobell
      Tells mhl	to ring	the terminal bell at the end of	each page. This	is
      the default behavior. You	can suppress this by using the -nobell
      option.

      This option takes	effect only if the profile entry moreproc is defined
      but empty, and if	mhl is outputting to a terminal. If the	moreproc
      entry is defined and non-empty, and mhl is outputting to a terminal,
      then mhl causes the moreproc to be placed	between	the terminal and mhl,
      and the switches are ignored.

  -clear

  -noclear
      Tells mhl	to clear the screen at the end of each page, or	output a
      formfeed after each message. You can suppress this by using the
      -noclear option. The default behavior is -noclear.

      This option takes	effect only if the profile entry moreproc is defined
      but empty, and if	mhl is outputting to a terminal. If the	moreproc
      entry in the user's .mh_profile is defined and non-empty,	and mhl	is
      outputting to a terminal,	then mhl causes	the moreproc program to	be
      placed between the terminal and mhl, and the options are ignored.

      If the -clear option is used and the output of mhl is directed to	a
      terminal,	then mhl consults the $TERM and	$TERMCAP environment vari-
      ables to determine your terminal type in order to	find out how to	clear
      the screen. If the -clear	switch is used and the output of mhl is	not
      directed to a terminal (if, for example, it is directed to a pipe	or a
      file), then mhl sends a formfeed after each message.

  -folder +foldername
      Sets the folder name. This is used by components in the mhl.format form
      file to output the message name. If you do not use this option, mhl
      consults the environmental variable $mhfolder.

  -form	formfile
      Specifies	the format file	used. If this option is	not given, mhl
      searches in your Mail directory for a file called	mhl.format; or,	if
      this file	does not exist,	it uses	the system default file
      /usr/lib/mh/mhl.format.

  -help
      Prints a list of the valid options to this command.

  -length lines
      Sets the screen length. This defaults to the value indicated by $TER-
      MINFO, if	appropriate; otherwise,	it defaults to 40.

  -width columns
      Sets the screen width. This defaults to the value	indicated by $TER-
      MINFO, if	appropriate; otherwise,	it defaults to 80.

  -moreproc program

  -nomoreproc
      Overrides	the default moreproc program.  Note that mhl never starts a
      moreproc if invoked on a hardcopy	terminal.

  The defaults for this	command	are:

       -bell
       -noclear
       -length	40
       -width  80

DESCRIPTION

  The mhl command is a program for listing formatted messages, which can be
  used as a replacement	for more, the default showproc program.

  As with more,	each of	the messages specified as arguments (or	the standard
  input) are output. If	more than one message file is specified, you are
  prompted prior to each one, and a <RETURN> or	<EOT> begins the output.
  <RETURN> clears the screen (if appropriate), and <EOT>, usually <CTRL/D>,
  suppresses the screen	clear. An <INTERRUPT>, usually <CTRL/C>, aborts	the
  current message output, prompting for	the next message, if there is one.  A
  <QUIT>, usually <CTRL/E>, terminates the program without generating a	core
  dump.

  The mhl command operates in two phases: it reads and parses the format
  file;	then it	processes each message (file). During the first	phase, an
  internal description of the format is	produced as a structured list. In the
  second phase,	this list is traversed for each	message, and message informa-
  tion is output according to the instructions contained in the	format file.

  The Form File	mhl.format


  The mhl.format form file contains information	controlling screen clearing,
  screen size, wrap-around control, transparent	text, component	ordering, and
  component formatting.	A list of components that should be ignored may	also
  be specified,	and some special components are	defined	to provide added
  functionality. Message output	is in the order	specified by the order in the
  format file.

  Each line of the mhl.format file has one of the following formats:

       ;comment
       :cleartext
       variable[variable...]
       component:[variable...]

  A line beginning with	a semi colon (;) is a comment, and is ignored.	A
  line beginning with a	colon (:) is clear text, and is	output exactly as it
  is. A	line containing	only a colon (:) produces a blank line in the output.
  A line beginning with	component: defines the format for the specified	com-
  ponent. Remaining lines define the global environment. Examples of these
  are given below, together with the system default form file.

  If variables or arguments follow a component,	they apply only	to that	com-
  ponent; otherwise, their effect is global. Since the whole format is parsed
  before any output processing,	the last global	switch setting for a variable
  applies to the whole message,	provided that the variable is used in a	glo-
  bal context (bell, clearscreen, width, length). All of the current vari-
  ables	and their arguments are	shown in the following table:

  _______________________________________________________________
  Variable	   Type	      Semantics
  _______________________________________________________________
  width		   integer    screen width or component	width
  length	   integer    screen length or component length
  offset	   integer    positions	to indent the component
  overflowtext	   string     text to use at the beginning of an
			      overflow line
  overflowoffset   integer    positions	to indent overflow lines
  compwidth	   integer

			      positions	to indent component text
			      after the	first line is output
  uppercase	   option

			      output text of this component in
			      all
			      upper case
  nouppercase	   option     do not use uppercase
  clearscreen	   option/G   clear the	screen prior to	each page
  noclearscreen	   option/G   do not clear the screen
  bell		   option/G

			      ring the bell at the end of each
			      page
  nobell	   option/G   disable bell
  component	   string/L

			      name to use instead of component
			      for this component
  nocomponent	   option

			      do not output component: for this
			      component
  center	   option

			      center component on line (works for
			      one-line components only)
  nocenter	   option     do not center
  leftadjust	   option

			      strip off	leading	white-space on
			      each line	of text
  noleftadjust	   option     do not leftadjust
  compress	   option     change newlines in text to spaces
  nocompress	   option     do not compress
  formatfield	   string     format string for	this component
  addrfield	   option     field contains addresses
  datefield	   option     field contains dates
  _______________________________________________________________

  To specify the value of integer-valued and string-valued variables, follow
  their	name with an equals-sign (=) and the value. Integer-valued variables
  are given decimal values, while string-valued	variables are given arbitrary
  text bracketed by double-quotes. If a	value is suffixed by /G	or /L, then
  its value is useful in a global-only or local-only context (respectively).
  A line of the	form:

       ignores=component,...

  specifies a list of components which are never output.

  The component	MessageName outputs the	actual message name (file name)	pre-
  ceded	by the folder name if one is specified or found	in the environment.
  The format is	identical to that produced by the -header option to show.

  The component	Extras outputs all of the components of	the message which
  were not matched by explicit components, or included in the ignore list. If
  this component is not	specified, an ignore list is not needed	since all
  non-specified	components are ignored.

  If -nocomponent is not specified, then the component name is output as it
  appears in the format	file.


  The variable formatfield specifies a format string; see mh-format(4).	 The
  variables addrfield and datefield, which are mutually	exclusive, control
  the interpretation of	the escapes.

  By default, mhl does not apply any formatting	string to fields containing
  address or dates; see	mh-mail(4) for a list of these fields. This results
  in faster operation since mhl	must parse both	addresses and dates in order
  to apply a format string to them.  If	desired, mhl can be given a default
  format string	for either address or date fields, but not both. To do this,
  on a global line specify either the variable addrfield or the	variable
  datefield, along with	the variable formatfield.

PROFILE	COMPONENTS

  Path:	To determine your Mail directory

  moreproc: Program to use as interactive front-end

EXAMPLES

  The first example gives a typical line of a form file:

       width=80,length=40,clearscreen,overflowtext="***",overflowoffset=5

  The first two	elements define	the screen width to be 80 characters, and the
  screen length	to be 40 lines.	The next element, clearscreen, specifies that
  the screen should be cleared prior to	each page.  The	next element, over-
  flowoffset=5,	states that the	overflow indentation is	5. The final element,
  overflowtext="***", specifies	that overflow text should be optionged with
  three	asterisks.

  The system default form file,	/usr/lib/mh/mhl.format,	is:

       : -- using template mhl.format -	-
       overflowtext="***",overflowoffset=5
       leftadjust,compwidth=9
       ignores=msid,msgid,message-id,received
       Date:formatfield="%<(nodate{text})%{text}%|%(pretty{text})%>"
       To:
       cc:
       :
       From:
       Subject:
       :
       extras:nocomponent
       :
       body:nocomponent,overflowtext=,overflowoffset=0,noleftadjust

FILES

  /usr/lib/mh/mhl.format
      The system default form file, used to format message.

  <&lt;mh-dir>&gt;/mhl.format
      The user-supplied	alternate to the system	default	form file.

  $HOME/.mh_profile
      The user profile.



SEE ALSO

  more(1), show(1), mh_profile(4), ap(8), dp(8)