Provided by: mmh_0.4-2_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
rtrim flag trim whitespace at end of text lines
nortrim flag retain whitespace at end of text lines (default)
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. This option supports some simple
globbing, so a '*' at the end of a component will match for all components which start
which the string. When you want to match a component which ends with a '*', you can
escape the '*' with a '\'.
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'.