MHL(1) [mh.6] MHL(1)
NAME
mhl - produce formatted listings of MH messages
SYNOPSIS
/usr/contrib/mh/lib/mhl [-bell] [-nobell] [-clear]
[-noclear] [-folder +folder] [-form formfile]
[-length lines] [-width columns] [-moreproc program]
[-nomoreproc] [files ...] [-help]
DESCRIPTION
Mhl is a formatted message listing program. It can be
used as a replacement for more (1) (the default
showproc ). As with more, each of the messages specified
as arguments (or the standard input) will be output. If
more than one message file is specified, the user will be
prompted prior to each one, and a <RETURN> or <EOT> will
begin the output, with <RETURN> clearing the screen (if
appropriate), and <EOT> (usually CTRL-D) suppressing the
screen clear. An <INTERRUPT> (usually CTRL-C) will abort
the current message output, prompting for the next message
(if there is one), and a <QUIT> (usually CTRL-\) will ter-
minate the program (without core dump).
The `-bell' option tells mhl to ring the terminal's bell
at the end of each page, while the `-clear' option tells
mhl to clear the scree at the end of each page (or output
a formfeed after each message). Both of these switches
(and their inverse counterparts) take effect only if the
profile entry moreproc is defined but empty, and mhl is
outputting to a terminal. If the moreproc entry is
defined and non-empty, and mhl is outputting to a termi-
nal, then mhl will cause the moreproc to be placed between
the terminal and mhl and the switches are ignored. Fur-
thermore, if the `-clear' switch is used and mhl's output
is directed to a terminal, then mhl will consult the $TERM
and $TERMCAP envariables to determine the user's terminal
type in order to find out how to clear the screen. If the
`-clear' switch is used and mhl's output is not directed
to a terminal (e.g., a pipe or a file), then mhl will send
a formfeed after each message.
To override the default moreproc and the profile entry,
use the `-moreproc program' switch.
The `-length length' and `-width width' switches set the
screen length and width, respectively. These default to
the values indicated by $TERMCAP, if appropriate, other-
wise they default to 40 and 80, respectively.
The default format file used by mhl is called mhl.format
(which is first searched for in the user's MH directory,
and then sought in the /usr/contrib/mh/lib directory),
this can be changed by using the `-form formatfile'
switch.
MH April 22, 1986 1
MHL(1) [mh.6] MHL(1)
Finally, the `-folder +folder' switch sets the MH folder
name, which is used for the messagename: field described
below. The envariable $mhfolder is consulted for the
default value, which show, next, and prev initialize
appropriately.
Mhl operates in two phases: 1) read and parse the format
file, and 2) process each message (file). During phase 1,
an internal description of the format is produced as a
structured list. In phase 2, this list is walked for each
message, outputting message information under the format
constraints from the format file.
The mhl.format form file contains information controlling
screen clearing, screen size, wrap-around control, trans-
parent text, component ordering, and component formatting.
Also, a list of components to ignore may be specified, and
a couple of special components are defined to provide
added functionality. Message output will be in the order
specified by the order in the format file.
Each line of mhl.format has one of the formats:
;comment
:cleartext
variable[,variable...]
component:[variable,...]
A line beginning with a `;' is a comment, and is ignored.
A line beginning with a `:' is clear text, and is output
exactly as is. A line containing only a `:' produces a
blank line in the output. A line beginning with compo-
nent: defines the format for the specified component, and
finally, remaining lines define the global environment.
For example, the line:
width=80,length=40,clearscreen,overflowtext="***",overflowoffset=5
defines the screen size to be 80 columns by 40 rows, spec-
ifies that the screen should be cleared prior to each
page, that the overflow indentation is 5, and that over-
flow text should be flagged with ***.
Following are all of the current variables and their argu-
ments. If they follow a component, they apply only to
that component, otherwise, their affect 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 if that variable is used in a global
context (i.e., bell, clearscreen, width, length).
variable type semantics
width integer screen width or component width
MH April 22, 1986 2
MHL(1) [mh.6] MHL(1)
length integer screen length or component length
offset integer positions to indent 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 flag output text of this component in all
upper case
nouppercase flag don't uppercase
clearscreen flag/G clear the screen prior to each page
noclearscreen flag/G don't clearscreen
bell flag/G ring the bell at the end of each page
nobell flag/G don't bell
component string/L name to use instead of component for
this component
nocomponent flag don't output component: for this
component
center flag center component on line (works for
one-line components only)
nocenter flag don't center
leftadjust flag strip off leading whitespace on each
line of text
noleftadjust flag don't leftadjust
compress flag change newlines in text to spaces
nocompress flag don't compress
formatfield string format string for this component
addrfield flag field contains addresses
datefield flag 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 arbirtray 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 (case-insensitive) will output
the actual message name (file name) preceded 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 will output 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
MH April 22, 1986 3
MHL(1) [mh.6] MHL(1)
non-specified components will be ignored.
If nocomponent is NOT specified, then the component name
will be output as it appears in the format file.
The default format is:
: -- using template mhl.format --
overflowtext="***",overflowoffset=5
leftadjust,compwidth=9
ignores=msgid,message-id,received
Date:formatfield="%<(nodate{text})%{text}%|%(pretty{text})%>"
To:
cc:
:
From:
Subject:
:
extras:nocomponent
:
body:nocomponent,overflowtext=,overflowoffset=0,noleftadjust
The variable formatfield specifies a format string (see
mh-format(5)). 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 (5) for a
list of these fields). Note that 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.
FILES
/usr/contrib/mh/lib/mhl.format The message template
or <mh-dir>/mhl.format Rather than the standard template
$HOME/.mh_profile The user profile
PROFILE COMPONENTS
moreproc: Program to use as interactive front-end
SEE ALSO
show(1), ap(8), dp(8)
DEFAULTS
`-bell'
`-noclear'
`-length 40'
`-width 80'
MH April 22, 1986 4
MHL(1) [mh.6] MHL(1)
CONTEXT
None
BUGS
There should be some way to pass `bell' and `clear' infor-
mation to the front-end.
On hosts where MH was configured with the BERK option,
address parsing is not enabled.
MH April 22, 1986 5