.MH "Miscellaneous Commands"
.#
.SH "Comments"
It is rare that a document
survives its writing under the pen of just one author or
editor.  More frequently, several different people
are likely to put in their two cents worth concerning its
format or content.  So, if the author is particularly attached
to something he has written, he is well advised to say so.
Comments are an ideal vehicle for this purpose and are easily
introduced  with the 'comment' command
.be
 [bf .#] <commentary text>
.ee
Everything after the [bf #]
up to and including the next newline character is completely
ignored by 'fmt'.
.#
.SH "Boldfacing and Underlining"
'Fmt' makes provisions for [bf boldfacing] and [ul underlining]
lines or parts thereof with two commands:
.be
 [bf .bf] N
.ee
boldfaces the next N lines of input text, while
.be
 [bf .ul] N
.ee
underlines the next N lines of input text.  In both cases, if N is
omitted, a value of one is assumed. Neither command causes a
break, allowing single words or phrases to be boldfaced or
underlined without affecting the rest of the output line.
.pp
It is also possible to use the two in combination. For instance,
the heading at the beginning of the table of contents was produced
by a sequence of commands and text similar to the following:
.be 3
 [bf .bf]
 [bf .ul]
 TABLE OF CONTENTS
.ee
As with the 'center' command, these two commands are often
used to bracket the lines to be affected by
specifying a huge parameter value with the first occurrence
of the command and a value of zero with the second:
.be 9
 [bf .bf] 1000
 [bf .ul] 1000
 lots of lines
 to be
 boldfaced
 and
 underlined
 [bf .bf] 0
 [bf .ul] 0
.ee
.#
.SH "Control Characters"
As  mentioned in the first section, command lines are
distinguished from text by the presence of a 'control character'
in column one.  In all the examples cited thus far,
a period has been used
to represent the control character.  It is possible
to select any character for this purpose.  In fact,
several occasions arose in the writing of this guide which called for
use of an alternate control character, particularly in the construction
of the command summaries at the end of each section.
The 'control-character' command may be used anywhere to
select a new value:
.be
 [bf .cc] <char>
.ee
The parameter <char>, which may be any single character, becomes the
new control character.  If the parameter is omitted, the familiar
period is reinstated.
.pp
It has been shown that many commands automatically cause a break before
they perform their function.  When
this presents a problem, it can be altered.
If instead of using the basic control
character   the 'no-break' control character is used to introduce
a command, the automatic break that would normally result is
suppressed.  The standard no-break control character is the
grave accent ("`"), but may easily be changed with the following
command:
.be
 [bf .c2] <char>
.ee
As with the [bf cc]
command, the parameter may be any single character, or may be
omitted if the default value is desired.
.#
.SH "Prompting"
Brief, one-line messages may be written directly to the user's terminal
using the 'prompt' command
.be
 [bf .er] <brief, one-line message>
.ee
The text that is actually written to the terminal starts with
the first non-blank character following the command name, and
continues up to, but not including, the next newline character.
If a newline character should be included in the message, the
escape sequence
.be
 @@n
.ee
may be used.  Leading blanks may also be included in the
message by preceding the message with a quote or an apostrophe.
'Fmt' will discard this character, but will then print the
rest of the
message verbatim.  For instance,
.be
 [bf .er] '          this is a message with 10 leading blanks
.ee
would write the following text on the terminal, leaving the
cursor or carriage at the end of the message
.be
           this is a message with 10 leading blanks
.ee
.ne 4
For a multiple-line message, try
.be
 [bf .er] multiple@@nline@@nmessage@@n
.ee
The output  should look like this:
.be 3
 multiple
 line
 message
.ee
.pp
Prompts are particularly useful in form letter applications
where there may be several pieces of information that
'fmt' has to ask for in the course of its work.
The next section describes how 'fmt' can dynamically obtain
information from the user.
.#
.SH "Premature Termination"
If 'fmt' should ever encounter an 'exit' command
.be
 [bf .ex]
.ee
in the course of doing its job, it will cause a break and
exit immediately to the Subsystem.
.#
.BT 26  "Summary - Miscellaneous Commands"
?RQ  .#  -  -  no
Introduce a comment.
?RQ  ".bf N"  N=0  N=1  no
Boldface N input text lines.
?RQ  ".c2 c"  `  `  no
Set no-break control character.
?RQ  ".cc c"  .  .  no
Set basic control character.
?RQ  ".er text"  -  ignored  no
Write a message to the terminal.
?RQ  .ex  -  -  yes
Exit immediately to the Subsystem.
?RQ  ".ul N"  N=0  N=1  no
Underline N input text lines.
?ET
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