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125 lines
3.8 KiB
Plaintext
125 lines
3.8 KiB
Plaintext
.\" This module is believed to contain source code proprietary to AT&T.
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.\" Use and redistribution is subject to the Berkeley Software License
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.\" Agreement and your Software Agreement with AT&T (Western Electric).
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.\"
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.\" @(#)tt07 8.1 (Berkeley) 6/8/93
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.\" Copyright (C) Caldera International Inc. 2001-2002. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions are
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.\" met:
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.\"
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.\" Redistributions of source code and documentation must retain the above
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.\" copyright notice, this list of conditions and the following
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.\" disclaimer.
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.\"
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.\" Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" All advertising materials mentioning features or use of this software
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.\" must display the following acknowledgement:
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.\"
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.\" This product includes software developed or owned by Caldera
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.\" International, Inc. Neither the name of Caldera International, Inc.
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.\" nor the names of other contributors may be used to endorse or promote
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.\" products derived from this software without specific prior written
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.\" permission.
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.\"
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.\" USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
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.\" INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
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.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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.\" DISCLAIMED. IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR
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.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
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.\" OR OTHERWISE) RISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
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.\" IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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.\"
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.\" $FreeBSD$
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.\"
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.NH
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Strings
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.PP
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Obviously if a paper contains a large number of occurrences
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of an acute accent over a letter `e',
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typing
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.BD \eo"e\e\'"
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for each \*e
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would be a great nuisance.
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.PP
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Fortunately,
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.UL troff
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provides a way in which you can store an arbitrary
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collection of text in a `string',
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and thereafter use the string name as a shorthand
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for its contents.
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Strings are one of several
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.UL troff
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mechanisms whose judicious use
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lets you type a document
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with less effort and organize
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it
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so that extensive format changes
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can be made with few editing changes.
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.PP
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A reference to a string is replaced by whatever
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text
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the string was defined as.
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Strings are defined with the command
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.BD .ds .
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The line
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.P1
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\&^ds e \eo"e\e'"
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.P2
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defines the string
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.BD e
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to have the value
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.BD \eo"e\e\'"
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.PP
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String names may be either one or two characters long,
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and are referred to by
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.BD \e*x
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for one character names or
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.BD \e*(xy
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for two character names.
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Thus to get
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t\*el\*ephone,
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given the definition of the string
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.BD e
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as above,
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we can say
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t\e*el\e*ephone.
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.PP
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If a string must begin with blanks, define it as
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.P1
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\&.ds xx " text
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.P2
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The double quote signals the beginning of the definition.
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There is no trailing quote;
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the end of the line terminates the string.
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.PP
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A string may actually be several lines long;
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if
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.UL troff
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encounters a
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.BD \e
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at the end of
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.ul
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any
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line, it is thrown away and the next line
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added to the current one.
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So you can make a long string simply by ending each line
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but the last with a backslash:
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.P1
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\&^ds xx this \e
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is a very \e
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long string
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.P2
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.PP
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Strings may be defined in terms of other strings, or even in terms of themselves;
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we will discuss some of these possibilities later.
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