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package Text::Wrap; | |
use warnings::register; | |
require Exporter; | |
@ISA = qw(Exporter); | |
@EXPORT = qw(wrap fill); | |
@EXPORT_OK = qw($columns $break $huge); | |
$VERSION = 2013.0523; | |
$SUBVERSION = 'modern'; | |
use 5.010_000; | |
use vars qw($VERSION $SUBVERSION $columns $debug $break $huge $unexpand $tabstop $separator $separator2); | |
use strict; | |
BEGIN { | |
$columns = 76; # <= screen width | |
$debug = 0; | |
$break = '(?=\s)\X'; | |
$huge = 'wrap'; # alternatively: 'die' or 'overflow' | |
$unexpand = 1; | |
$tabstop = 8; | |
$separator = "\n"; | |
$separator2 = undef; | |
} | |
my $CHUNK = qr/\X/; | |
sub _xlen(_) { scalar(() = $_[0] =~ /$CHUNK/g) } | |
sub _xpos(_) { _xlen( substr( $_[0], 0, pos($_[0]) ) ) } | |
use Text::Tabs qw(expand unexpand); | |
sub wrap | |
{ | |
my ($ip, $xp, @t) = @_; | |
local($Text::Tabs::tabstop) = $tabstop; | |
my $r = ""; | |
my $tail = pop(@t); | |
my $t = expand(join("", (map { /\s+\z/ ? ( $_ ) : ($_, ' ') } @t), $tail)); | |
my $lead = $ip; | |
my $nll = $columns - _xlen(expand($xp)) - 1; | |
if ($nll <= 0 && $xp ne '') { | |
my $nc = _xlen(expand($xp)) + 2; | |
warnings::warnif "Increasing \$Text::Wrap::columns from $columns to $nc to accommodate length of subsequent tab"; | |
$columns = $nc; | |
$nll = 1; | |
} | |
my $ll = $columns - _xlen(expand($ip)) - 1; | |
$ll = 0 if $ll < 0; | |
my $nl = ""; | |
my $remainder = ""; | |
use re 'taint'; | |
pos($t) = 0; | |
while ($t !~ /\G(?:$break)*\Z/gc) { | |
if ($t =~ /\G((?:(?=[^\n])\X){0,$ll})($break|\n+|\z)/xmgc) { | |
$r .= $unexpand | |
? unexpand($nl . $lead . $1) | |
: $nl . $lead . $1; | |
$remainder = $2; | |
} elsif ($huge eq 'wrap' && $t =~ /\G((?:(?=[^\n])\X){$ll})/gc) { | |
$r .= $unexpand | |
? unexpand($nl . $lead . $1) | |
: $nl . $lead . $1; | |
$remainder = defined($separator2) ? $separator2 : $separator; | |
} elsif ($huge eq 'overflow' && $t =~ /\G((?:(?=[^\n])\X)*?)($break|\n+|\z)/xmgc) { | |
$r .= $unexpand | |
? unexpand($nl . $lead . $1) | |
: $nl . $lead . $1; | |
$remainder = $2; | |
} elsif ($huge eq 'die') { | |
die "couldn't wrap '$t'"; | |
} elsif ($columns < 2) { | |
warnings::warnif "Increasing \$Text::Wrap::columns from $columns to 2"; | |
$columns = 2; | |
return ($ip, $xp, @t); | |
} else { | |
die "This shouldn't happen"; | |
} | |
$lead = $xp; | |
$ll = $nll; | |
$nl = defined($separator2) | |
? ($remainder eq "\n" | |
? "\n" | |
: $separator2) | |
: $separator; | |
} | |
$r .= $remainder; | |
print "-----------$r---------\n" if $debug; | |
print "Finish up with '$lead'\n" if $debug; | |
my($opos) = pos($t); | |
$r .= $lead . substr($t, pos($t), length($t) - pos($t)) | |
if pos($t) ne length($t); | |
print "-----------$r---------\n" if $debug;; | |
return $r; | |
} | |
sub fill | |
{ | |
my ($ip, $xp, @raw) = @_; | |
my @para; | |
my $pp; | |
for $pp (split(/\n\s+/, join("\n",@raw))) { | |
$pp =~ s/\s+/ /g; | |
my $x = wrap($ip, $xp, $pp); | |
push(@para, $x); | |
} | |
# if paragraph_indent is the same as line_indent, | |
# separate paragraphs with blank lines | |
my $ps = ($ip eq $xp) ? "\n\n" : "\n"; | |
return join ($ps, @para); | |
} | |
1; | |
__END__ | |
=head1 NAME | |
Text::Wrap - line wrapping to form simple paragraphs | |
=head1 SYNOPSIS | |
B<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); | |
B<Example 2> | |
use Text::Wrap qw(wrap $columns $huge); | |
$columns = 132; # Wrap at 132 characters | |
$huge = 'die'; | |
$huge = 'wrap'; | |
$huge = 'overflow'; | |
B<Example 3> | |
use Text::Wrap; | |
$Text::Wrap::columns = 72; | |
print wrap('', '', @text); | |
=head1 DESCRIPTION | |
C<Text::Wrap::wrap()> is a very simple paragraph formatter. It formats a | |
single paragraph at a time by breaking lines at word boundaries. | |
Indentation is controlled for the first line (C<$initial_tab>) and | |
all subsequent lines (C<$subsequent_tab>) independently. Please note: | |
C<$initial_tab> and C<$subsequent_tab> are the literal strings that will | |
be used: it is unlikely you would want to pass in a number. | |
C<Text::Wrap::fill()> is a simple multi-paragraph formatter. It formats | |
each paragraph separately and then joins them together when it's done. It | |
will destroy any whitespace in the original text. It breaks text into | |
paragraphs by looking for whitespace after a newline. In other respects, | |
it acts like wrap(). | |
C<wrap()> compresses trailing whitespace into one newline, and C<fill()> | |
deletes all trailing whitespace. | |
Both C<wrap()> and C<fill()> return a single string. | |
Unlike the old Unix fmt(1) utility, this module correctly accounts for | |
any Unicode combining characters (such as diacriticals) that may occur | |
in each line for both expansion and unexpansion. These are overstrike | |
characters that do not increment the logical position. Make sure | |
you have the appropriate Unicode settings enabled. | |
=head1 OVERRIDES | |
C<Text::Wrap::wrap()> has a number of variables that control its behavior. | |
Because other modules might be using C<Text::Wrap::wrap()> it is suggested | |
that you leave these variables alone! If you can't do that, then | |
use C<local($Text::Wrap::VARIABLE) = YOURVALUE> when you change the | |
values so that the original value is restored. This C<local()> trick | |
will not work if you import the variable into your own namespace. | |
Lines are wrapped at C<$Text::Wrap::columns> columns (default value: 76). | |
C<$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 | |
C<$columns - 1>. | |
It is possible to control which characters terminate words by | |
modifying C<$Text::Wrap::break>. Set this to a string such as | |
C<'[\s:]'> (to break before spaces or colons) or a pre-compiled regexp | |
such as C<qr/[\s']/> (to break before spaces or apostrophes). The | |
default is simply C<'\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 C<$Text::Wrap::break> to a regular expression that doesn't | |
eat any characters (perhaps just a forward look-ahead assertion) will | |
cause warnings. | |
Beginner note: In example 2, above C<$columns> is imported into | |
the local namespace, and set locally. In example 3, | |
C<$Text::Wrap::columns> is set in its own namespace without importing it. | |
C<Text::Wrap::wrap()> starts its work by expanding all the tabs in its | |
input into spaces. The last thing it does it to turn spaces back | |
into tabs. If you do not want tabs in your results, set | |
C<$Text::Wrap::unexpand> to a false value. Likewise if you do not | |
want to use 8-character tabstops, set C<$Text::Wrap::tabstop> to | |
the number of characters you do want for your tabstops. | |
If you want to separate your lines with something other than C<\n> | |
then set C<$Text::Wrap::separator> to your preference. This replaces | |
all newlines with C<$Text::Wrap::separator>. If you just want to | |
preserve existing newlines but add new breaks with something else, set | |
C<$Text::Wrap::separator2> instead. | |
When words that are longer than C<$columns> are encountered, they | |
are broken up. C<wrap()> adds a C<"\n"> at column C<$columns>. | |
This behavior can be overridden by setting C<$huge> to | |
'die' or to 'overflow'. When set to 'die', large words will cause | |
C<die()> to be called. When set to 'overflow', large words will be | |
left intact. | |
Historical notes: 'die' used to be the default value of | |
C<$huge>. Now, 'wrap' is the default value. | |
=head1 EXAMPLES | |
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; | |
$Text::Wrap::separator="|"; | |
print wrap("","","This is a bit of text that forms a normal book-style paragraph"); | |
Result: | |
"This is a bit of|text that forms a|normal book-style|paragraph" | |
=head1 SUBVERSION | |
This module comes in two flavors: one for modern perls (5.10 and above) | |
and one for ancient obsolete perls. The version for modern perls has | |
support for Unicode. The version for old perls does not. You can tell | |
which version you have installed by looking at C<$Text::Wrap::SUBVERSION>: | |
it is C<old> for obsolete perls and C<modern> for current perls. | |
This man page is for the version for modern perls and so that's probably | |
what you've got. | |
=head1 SEE ALSO | |
For correct handling of East Asian half- and full-width characters, | |
see L<Text::WrapI18N>. For more detailed controls: L<Text::Format>. | |
=head1 AUTHOR | |
David Muir Sharnoff <[email protected]> with help from Tim Pierce and | |
many many others. | |
=head1 LICENSE | |
Copyright (C) 1996-2009 David Muir Sharnoff. | |
Copyright (C) 2012-2013 Google, Inc. | |
This module may be modified, used, copied, and redistributed at your own risk. | |
Although allowed by the preceding license, please do not publicly | |
redistribute modified versions of this code with the name "Text::Wrap" | |
unless it passes the unmodified Text::Wrap test suite. | |