Provided by: mmh_0.3-3_amd64 
NAME
mhl - produce formatted listings of mh messages
SYNOPSIS
mhl [-form formfile] [-width columns] [files ...] [-Version] [-help]
DESCRIPTION
Mhl is an mmh command for filtering and/or displaying text messages. It is the default method of
displaying text messages for mmh (it is the default showproc).
The -width width switch sets the screen width. This defaults to the value indicated by $TERMCAP, if
appropriate, otherwise it defaults to 80.
The default format file used by mhl is called `mhl.format'. mhl will first search for this file in the
user's mmh directory, and will then search in the directory /etc/mmh. This default can be changed by
using the -form formatfile switch. Note: In contrast to any other mmh tool, the -form switch does only
take file names, but no format strings with a prepended equal sign `='.
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 format file can contain information controlling screen size, wrap-around control, transparent 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 a format file has one of the following forms:
;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 `component:' defines the format for the specified component,
• Remaining lines define the global environment.
For example, the line:
width=80,overflowtext="***",overflowoffset=5
defines the screen size to be 80 columns by 40 rows, specifies that the overflow indentation is 5, and
that overflow text should be flagged with `***'.
Following are all of the current variables and their arguments. 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., width).
variable type semantics
width integer screen width or component width
length integer 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
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
split flag don't combine multiple fields into
a single field
nosplit flag combine multiple fields into
a single field
newline flag print newline at end of components
(this is the default)
nonewline flag don't print newline at end of components
formatfield string format string for this component
(see below)
decode flag decode text as RFC-2047 encoded
header field
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 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' (case-insensitive) will output the message file name as a one-line header,
similar to show. E.g. ``(Message 42)''
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 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 file is:
; mhl.format
;
; default message filter for `show'
;
:
overflowtext="***",overflowoffset=5
leftadjust,compwidth=9
ignores=msgid,message-id,received,content-type,content-transfer-encoding,content-id
Date:formatfield="%<(nodate{text})%{text}%|%(pretty{text})%>"
From:decode
To:decode
Cc:decode
Subject:decode
:
extras:nocomponent
:
body:nocomponent,overflowtext=,overflowoffset=0,noleftadjust
The variable `formatfield' specifies a format string (see mh-format(5)). The flag variables `addrfield'
and `datefield' (which are mutually exclusive), tell mhl to interpret the escapes in the format string as
either addresses or dates, respectively.
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 flag addrfield or datefield, along with the appropriate formatfield variable string.
FILES
/etc/mmh/mhl.format The message template
or $HOME/.mmh/mhl.format Rather than the standard template
$HOME/.mmh/profile The user profile
PROFILE COMPONENTS
none
SEE ALSO
show(1), ap(8), dp(8)
DEFAULTS
`-width 80'
CONTEXT
None
BUGS
In contrast to any other mmh tool, the -form switch does only take file names, but no format strings with
a prepended equal sign `='.
The `nonewline' option interacts badly with `compress' and `split'.