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
use Text::Wrap;
$Text::Wrap::columns = 72;
print wrap('', '', @text);Text::Wrap::wrap() is a very simple paragraph formatter. It formats a single paragraph at a time by breaking lines at word boundaries. Indentation is controlled for the first line ($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
ENDResult:
" 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.