Text::WideChar::Util - Routines for text containing wide characters


This document describes version 0.172 of Text::WideChar::Util (from Perl distribution Text-WideChar-Util), released on 2021-04-14.


 use Text::WideChar::Util qw(
     mbpad pad mbswidth mbswidth_height mbtrunc trunc mbwrap wrap);

 # get width as well as number of lines
 say mbswidth_height("red\n红色"); # => [4, 2]

 # wrap text to a certain column width
 say mbwrap("....", 40);

 # pad (left, right, center) text to specified column width, handle multilines
 say mbpad("foo", 10);                          # => "foo       "
 say mbpad("红色", 10, "left");                 # => "      红色"
 say mbpad("foo\nbarbaz\n", 10, "center", "."); # => "\n..barbaz..\n"

 # truncate text to a certain column width
 say mbtrunc("红色",  2); # => "红"
 say mbtrunc("红色",  3); # => "红"
 say mbtrunc("红red", 3); # => "红r"


This module provides routines for dealing with text containing wide characters (wide meaning occupying more than 1 column width in terminal).


Should we wrap at hyphens? Probably not. Both Emacs as well as Text::Wrap do not.


mbswidth($text) => INT

Like Text::CharWidth's mbswidth(), except implemented using Unicode::GCString->new($text)->columns.

mbswidth_height($text) => [INT, INT]

Like mbswidth(), but also gives height (number of lines). For example, mbswidth_height("foobar\nb\n") gives [6, 3].

length_height($text) => [INT, INT]

This is the non-wide version of mbswidth_height() and can be used if your text only contains printable ASCII characters and newlines.

mbwrap($text, $width, \%opts) => STR

Wrap $text to $width columns. Replaces multiple whitespaces with a single space.

It uses mbswidth() instead of Perl's length() which works on a per-character basis. Has some support for wrapping Kanji/CJK (Chinese/Japanese/Korean) text which do not have whitespace between words.


  • tab_width => INT (default: 8)

    Set tab width.

    Note that tab will only have effect on the indent. Tab between text will be replaced with a single space.

  • flindent => STR

    First line indent. If unspecified, will be deduced from the first line of text.

  • slindent => STD

    Subsequent line indent. If unspecified, will be deduced from the second line of text, or if unavailable, will default to empty string ("").

  • return_stats => BOOL (default: 0)

    If set to true, then instead of returning the wrapped string, function will return [$wrapped, $stats] where $stats is a hash containing some information like max_word_width, min_word_width.

  • keep_trailing_space => BOOL (default: 0)

    If set to true, then trailing space that separates words will be kept at the end of wrapped lines. This option is useful if you want to rejoin the lines later. Without this option set to true, wrapping this line at width=4 (quotes shown):

     "some long   line"

    will result in:


    While if this option is set to true, the result will be:

     "some "
     "long "

Performance: ~450/s on my Core i5 1.7GHz laptop for a 1KB of text.

wrap($text, $width, \%opts) => STR

Like mbwrap(), but uses character-based length() instead of column width-wise mbswidth(). Provided as an alternative to the venerable Text::Wrap's wrap() but with a different behaviour. This module's wrap() can reflow newline and its behavior is more akin to Emacs (try reflowing a paragraph in Emacs using M-q).

Performance: ~2000/s on my Core i5 1.7GHz laptop for a ~1KB of text. Text::Wrap::wrap() on the other hand is ~2500/s.

mbpad($text, $width[, $which[, $padchar[, $truncate]]]) => STR

Return $text padded with $padchar to $width columns. $which is either "r" or "right" for padding on the right (the default if not specified), "l" or "left" for padding on the right, or "c" or "center" or "centre" for left+right padding to center the text.

$padchar is whitespace if not specified. It should be string having the width of 1 column.

pad($text, $width[, $which[, $padchar[, $truncate]]]) => STR

The non-wide version of mbpad(), just like in mbwrap() vs wrap().

mbtrunc($text, $width) => STR

Truncate $text to $width columns. It uses mbswidth() instead of Perl's length(), so it can handle wide characters.

Does *not* handle multiple lines.

trunc($text, $width) => STR

The non-wide version of mbtrunc(), just like in mbwrap() vs wrap(). This is actually not much more than Perl's substr($text, 0, $width).


Why split functionalities of wide character and color support into multiple modules/distributions?

Performance (see numbers in the function description), dependency (Unicode::GCString is used for wide character support), and overhead (loading Unicode::GCString).


Please visit the project's homepage at


Source repository is at


Please report any bugs or feature requests on the bugtracker website

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.


Unicode::GCString which is consulted for visual width of characters. Text::CharWidth is about 2.5x faster but it gives weird results (-1 for characters like "\n" and "\t") and my Strawberry Perl installation fails to build it.

Text::ANSI::Util which can also handle text containing wide characters as well ANSI escape codes.

Text::WrapI18N which provides an alternative to wrap()/mbwrap() with comparable speed, though wrapping result might differ slightly. And the module currently uses Text::CharWidth.

Text::NonWideChar::Util contains non-wide version of some of the abovementioned routines (the non-wide version of the routines will eventually be moved here).

String::Pad, Text::Wrap


perlancar <>


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