4 .TH MHL %manext1% "%nmhdate%" MH.6.8 [%nmhversion%]
6 mhl \- produce formatted listings of nmh messages
11 .RB [ \-bell " | " \-nobell ]
12 .RB [ \-clear " | " \-noclear ]
32 command for filtering and/or displaying text
33 messages. It is the default method of displaying text messages for
40 each of the messages specified as arguments (or
41 the standard input) will be output. If more than one message file is
42 specified, the user will be prompted prior to each one, and a <RETURN>
43 or <EOT> will begin the output, with <RETURN> clearing the screen (if
44 appropriate), and <EOT> (usually CTRL\-D) suppressing the screen clear.
45 An <INTERRUPT> (usually CTRL\-C) will abort the current message output,
46 prompting for the next message (if there is one), and a <QUIT> (usually
47 CTRL-\\) will terminate the program (without core dump).
53 to ring the terminal's bell at the
54 end of each page, while the
59 screen at the end of each page (or output a formfeed after each message).
60 Both of these switches (and their inverse counterparts) take effect only
63 is defined but empty, and
65 is outputting to a terminal. If the
70 is outputting to a terminal, then
75 to be placed between the terminal and
77 and the switches are ignored. Furthermore, if the
80 used and \fImhl's\fR output is directed to a terminal, then
87 to determine the user's terminal type in order to find out how to clear
93 not directed to a terminal (e.g., a pipe or a file), then
96 send a formfeed after each message.
98 To override the default
100 and the profile entry, use the
107 if invoked on a hardcopy terminal.
115 switches set the screen
116 length and width, respectively. These default to the values indicated by
118 if appropriate, otherwise they default to 40 and 80, respectively.
120 The default format file used by
123 .RI \*(lq mhl.format \*(rq.
125 will first search for this file in the user's
127 directory, and will then search in the directory
130 can be changed by using the
134 Note: In contrast to any other
138 switch does only take file names, but no format strings with a prepended
147 which is used for the \*(lqmessagename:\*(rq field described below. The
150 is consulted for the default value,
156 initialize appropriately.
159 operates in two phases: 1) read and parse the format file, and
160 2) process each message (file). During phase 1, an internal description
161 of the format is produced as a structured list. In phase 2, this list
162 is walked for each message, outputting message information under the
163 format constraints from the format file.
165 The format file can contain information controlling screen clearing,
166 screen size, wrap\-around control, transparent text, component ordering,
167 and component formatting. Also, a list of components to ignore may be
168 specified, and a couple of \*(lqspecial\*(rq components are defined
169 to provide added functionality. Message output will be in the order
170 specified by the order in the format file.
172 Each line of a format file has one of the following forms:
178 variable[,variable...]
179 component:[variable,...]
184 A line beginning with a `;' is a comment, and is ignored.
186 A line beginning with a `:' is clear text, and is output exactly as is.
188 A line containing only a `:' produces a blank line in the output.
190 A line beginning with \*(lqcomponent:\*(rq defines the format for the specified
193 Remaining lines define the global environment.
195 For example, the line:
198 width=80,length=40,clearscreen,overflowtext="***",overflowoffset=5
201 defines the screen size to be 80 columns by 40 rows, specifies that the
202 screen should be cleared prior to each page, that the overflow indentation
203 is 5, and that overflow text should be flagged with \*(lq***\*(rq.
205 Following are all of the current variables and their arguments. If they
206 follow a component, they apply only to that component, otherwise, their
207 affect is global. Since the whole format is parsed before any output
208 processing, the last global switch setting for a variable applies to
209 the whole message if that variable is used in a global context (i.e.,
210 bell, clearscreen, width, length).
214 .ta \w'noclearscreen 'u +\w'integer/G 'u
215 .I variable type semantics
216 width integer screen width or component width
217 length integer screen length or component length
218 offset integer positions to indent \*(lqcomponent: \*(rq
219 overflowtext string text to use at the beginning of an
221 overflowoffset integer positions to indent overflow lines
222 compwidth integer positions to indent component text
223 after the first line is output
224 uppercase flag output text of this component in all
226 nouppercase flag don't uppercase
227 clearscreen flag/G clear the screen prior to each page
228 noclearscreen flag/G don't clearscreen
229 bell flag/G ring the bell at the end of each page
230 nobell flag/G don't bell
231 component string/L name to use instead of \*(lqcomponent\*(rq for
233 nocomponent flag don't output \*(lqcomponent: \*(rq for this
235 center flag center component on line (works for
236 one\-line components only)
237 nocenter flag don't center
238 leftadjust flag strip off leading whitespace on each
240 noleftadjust flag don't leftadjust
241 compress flag change newlines in text to spaces
242 nocompress flag don't compress
243 split flag don't combine multiple fields into
245 nosplit flag combine multiple fields into
247 newline flag print newline at end of components
248 (this is the default)
249 nonewline flag don't print newline at end of components
250 formatfield string format string for this component
252 decode flag decode text as RFC-2047 encoded
254 addrfield flag field contains addresses
255 datefield flag field contains dates
259 To specify the value of integer\-valued and string\-valued variables,
260 follow their name with an equals\-sign and the value. Integer\-valued
261 variables are given decimal values, while string\-valued variables
262 are given arbitrary text bracketed by double\-quotes. If a value is
263 suffixed by \*(lq/G\*(rq or \*(lq/L\*(rq, then its value is useful in
264 a global\-only or local\-only context (respectively).
269 ignores=component,...
272 specifies a list of components which are never output.
274 The component \*(lqMessageName\*(rq (case\-insensitive) will output the
275 actual message name (file name) preceded by the folder name if one is
276 specified or found in the environment. The format is identical to that
282 The component \*(lqExtras\*(rq will output all of the components of the
283 message which were not matched by explicit components, or included in
284 the ignore list. If this component is not specified, an ignore list is
285 not needed since all non\-specified components will be ignored.
287 If \*(lqnocomponent\*(rq is NOT specified, then the component name will
288 be output as it appears in the format file.
290 The default format file is:
298 The variable \*(lqformatfield\*(rq specifies a format string (see
300 The flag variables \*(lqaddrfield\*(rq and
301 \*(lqdatefield\*(rq (which are mutually exclusive), tell
303 to interpret the escapes in the format string as either addresses or
308 does not apply any formatting string to fields
309 containing address or dates (see
312 fields). Note that this results in faster operation since
314 must parse both addresses and dates in order to apply a format string
317 can be given a default format string for
318 either address or date fields (but not both). To do this, on a global
319 line specify: either the flag addrfield or datefield, along with the
320 appropriate formatfield variable string.
325 .ta \w'%etcdir%/ExtraBigFileName 'u
326 ^%etcdir%/mhl.format~^The message template
327 ^or $HOME/.mmh/mhl.format~^Rather than the standard template
328 ^$HOME/.mh/profile~^The user profile
331 .SH "PROFILE COMPONENTS"
335 .ta \w'ExtraBigProfileName 'u
336 ^moreproc:~^Program to use as interactive front\-end
340 show(1), ap(8), dp(8)
354 In contrast to any other
358 switch does only take file names, but no format strings with a prepended
361 There should be some way to pass `bell' and `clear' information to the
364 The \*(lqnonewline\*(rq option interacts badly with \*(lqcompress\*(rq