Obviously if a paper contains a large number of occurrences of an acute accent over a letter `e', typing \o"e\'"for each e' would be a great nuisance.
Fortunately, troff provides a way in which you can store an arbitrary collection of text in a `string', and thereafter use the string name as a shorthand for its contents. Strings are one of several troff mechanisms whose judicious use lets you type a document with less effort and organize it so that extensive format changes can be made with few editing changes.
A reference to a string is replaced by whatever
text
the string was defined as.
Strings are defined with the command
.dsThe line
^ds e \o"e\'"
defines the string
eto have the value
\o"e\'"
String names may be either one or two characters long, and are referred to by \*xfor one character names or \*(xyfor two character names. Thus to get te'le'phone, given the definition of the string eas above, we can say t\*el\*ephone.
If a string must begin with blanks, define it as
.ds xx " text
The double quote signals the beginning of the definition.
There is no trailing quote;
the end of the line terminates the string.
A string may actually be several lines long;
if
troff
encounters a
\at the end of
any
line, it is thrown away and the next line
added to the current one.
So you can make a long string simply by ending each line
but the last with a backslash:
^ds xx this \
is a very \
long string
Strings may be defined in terms of other strings, or even in terms of themselves; we will discuss some of these possibilities later.