Text::Wrap - line wrapping to form simple paragraphs
Example 1
- use Text::Wrap;
- $initial_tab = "\t"; # Tab before first line
- $subsequent_tab = ""; # All other lines flush left
- print wrap($initial_tab, $subsequent_tab, @text);
- print fill($initial_tab, $subsequent_tab, @text);
- $lines = wrap($initial_tab, $subsequent_tab, @text);
- @paragraphs = fill($initial_tab, $subsequent_tab, @text);
Example 2
- use Text::Wrap qw(wrap $columns $huge);
- $columns = 132; # Wrap at 132 characters
- $huge = 'die';
- $huge = 'wrap';
- $huge = 'overflow';
Example 3
Text::Wrap::wrap()
is a very simple paragraph formatter. It formats a
single paragraph at a time by breaking lines at word boundaries.
Indentation is controlled for the first line ($initial_tab
) and
all subsequent lines ($subsequent_tab
) independently. Please note:
$initial_tab
and $subsequent_tab
are the literal strings that will
be used: it is unlikely you would want to pass in a number.
Text::Wrap::fill() is a simple multi-paragraph formatter. It formats each paragraph separately and then joins them together when it's done. It will destroy any whitespace in the original text. It breaks text into paragraphs by looking for whitespace after a newline. In other respects it acts like wrap().
Both wrap()
and fill()
return a single string.
Text::Wrap::wrap()
has a number of variables that control its behavior.
Because other modules might be using Text::Wrap::wrap()
it is suggested
that you leave these variables alone! If you can't do that, then
use local($Text::Wrap::VARIABLE) = YOURVALUE
when you change the
values so that the original value is restored. This local() trick
will not work if you import the variable into your own namespace.
Lines are wrapped at $Text::Wrap::columns
columns (default value: 76).
$Text::Wrap::columns
should be set to the full width of your output
device. In fact, every resulting line will have length of no more than
$columns - 1
.
It is possible to control which characters terminate words by
modifying $Text::Wrap::break
. Set this to a string such as
'[\s:]'
(to break before spaces or colons) or a pre-compiled regexp
such as qr/[\s']/ (to break before spaces or apostrophes). The
default is simply '\s'
; that is, words are terminated by spaces.
(This means, among other things, that trailing punctuation such as
full stops or commas stay with the word they are "attached" to.)
Setting $Text::Wrap::break
to a regular expression that doesn't
eat any characters (perhaps just a forward look-ahead assertion) will
cause warnings.
Beginner note: In example 2, above $columns
is imported into
the local namespace, and set locally. In example 3,
$Text::Wrap::columns
is set in its own namespace without importing it.
Text::Wrap::wrap()
starts its work by expanding all the tabs in its
input into spaces. The last thing it does it to turn spaces back
into tabs. If you do not want tabs in your results, set
$Text::Wrap::unexpand
to a false value. Likewise if you do not
want to use 8-character tabstops, set $Text::Wrap::tabstop
to
the number of characters you do want for your tabstops.
If you want to separate your lines with something other than \n
then set $Text::Wrap::separator
to your preference. This replaces
all newlines with $Text::Wrap::separator
. If you just want to
preserve existing newlines but add new breaks with something else, set
$Text::Wrap::separator2
instead.
When words that are longer than $columns
are encountered, they
are broken up. wrap()
adds a "\n"
at column $columns
.
This behavior can be overridden by setting $huge
to
'die' or to 'overflow'. When set to 'die', large words will cause
die() to be called. When set to 'overflow', large words will be
left intact.
Historical notes: 'die' used to be the default value of
$huge
. Now, 'wrap' is the default value.
Code:
- print wrap("\t","",<<END);
- This is a bit of text that forms
- a normal book-style indented paragraph
- END
Result:
- " This is a bit of text that forms
- a normal book-style indented paragraph
- "
Code:
- $Text::Wrap::columns=20;
- $Text::Wrap::separator="|";
- print wrap("","","This is a bit of text that forms a normal book-style paragraph");
Result:
- "This is a bit of|text that forms a|normal book-style|paragraph"
For wrapping multi-byte characters: Text::WrapI18N. For more detailed controls: Text::Format.
David Muir Sharnoff <muir@idiom.org> with help from Tim Pierce and many many others. Copyright (C) 1996-2009 David Muir Sharnoff. This module may be modified, used, copied, and redistributed at your own risk. Publicly redistributed versions that are modified must use a different name.