Usually, a Texinfo file is processed both by TeX and by one of the Info formatting commands. Line, paragraph, or page breaks sometimes occur in the `wrong' place in one or other form of output. You must ensure that text looks right both in the printed manual and in the Info file.
For example, in a printed manual, page breaks may occur awkwardly in the middle of an example; to prevent this, you can hold text together using a grouping command that keeps the text from being split across two pages. Conversely, you may want to force a page break where none would occur normally. Fortunately, problems like these do not often arise. When they do, use the break, break prevention, or pagination commands.
The break commands create line and paragraph breaks:
@*
@sp n
The line-break-prevention command holds text together all on one line:
@w{text}
The pagination commands apply only to printed output, since Info files do not have pages.
@page
@group
@need mils
@*
: Generate Line Breaks
The @*
command forces a line break in both the printed manual and
in Info.
For example,
This line @* is broken @*in two places.
produces
This line is broken in two places.
(Note that the space after the first @*
command is faithfully
carried down to the next line.)
The @*
command is often used in a file's copyright page:
This is edition 2.0 of the Texinfo documentation,@* and is for ...
In this case, the @*
command keeps TeX from stretching the
line across the whole page in an ugly manner.
Please note: Do not write braces after an
@*
command; they are not needed.Do not write an
@refill
command at the end of a paragraph containing an@*
command; it will cause the paragraph to be refilled after the line break occurs, negating the effect of the line break.
@w
{text}: Prevent Line Breaks
@w{text}
outputs text and prohibits line breaks
within text.
You can use the @w
command to prevent TeX from automatically
hyphenating a long name or phrase that accidentally falls near the end
of a line.
You can copy GNU software from @w{@file{prep.ai.mit.edu}}.
produces
You can copy GNU software from `prep.ai.mit.edu'.
In the Texinfo file, you must write the @w
command and its
argument (all the affected text) all on one line.
Caution: Do not write an
@refill
command at the end of a paragraph containing an@w
command; it will cause the paragraph to be refilled and may thereby negate the effect of the@w
command.
@sp
n: Insert Blank Lines
A line beginning with and containing only @sp n
generates n blank lines of space in both the printed manual and
the Info file. @sp
also forces a paragraph break. For
example,
@sp 2
generates two blank lines.
The @sp
command is most often used in the title page.
@page
: Start a New Page
A line containing only @page
starts a new page in a printed
manual. The command has no effect on Info files since they are not
paginated. An @page
command is often used in the @titlepage
section of a Texinfo file to start the copyright page.
@group
: Prevent Page Breaks
The @group
command (on a line by itself) is used inside an
@example
or similar construct to begin an unsplittable vertical
group, which will appear entirely on one page in the printed output.
The group is terminated by a line containing only @end group
.
These two lines produce no output of their own, and in the Info file
output they have no effect at all.
Although @group
would make sense conceptually in a wide
variety of contexts, its current implementation works reliably only
within @example
and variants, and within @display
,
@format
, @flushleft
and @flushright
.
See section Quotations and Examples. (What all these commands have in
common is that each line of input produces a line of output.) In
other contexts, @group
can cause anomalous vertical
spacing.
This formatting requirement means that you should write:
@example @group ... @end group @end example
with the @group
and @end group
commands inside the
@example
and @end example
commands.
The @group
command is most often used to hold an example
together on one page. In this Texinfo manual, more than 100 examples
contain text that is enclosed between @group
and @end
group
.
If you forget to end a group, you may get strange and unfathomable
error messages when you run TeX. This is because TeX keeps
trying to put the rest of the Texinfo file onto the one page and does
not start to generate error messages until it has processed
considerable text. It is a good rule of thumb to look for a missing
@end group
if you get incomprehensible error messages in
TeX.
@need mils
: Prevent Page Breaks
A line containing only @need n
starts
a new page in a printed manual if fewer than n mils (thousandths
of an inch) remain on the current page. Do not use
braces around the argument n. The @need
command has no
effect on Info files since they are not paginated.
This paragraph is preceded by an @need
command that tells
TeX to start a new page if fewer than 800 mils (eight-tenths
inch) remain on the page. It looks like this:
@need 800 This paragraph is preceded by ...
The @need
command is useful for preventing orphans (single
lines at the bottoms of printed pages).