This module supplies features similar as wcwidth(3) and wcswidth(3) in C
language.

Characters have its own width on terminal depending on locale. For example,
ASCII characters occupy one column per character, east Asian fullwidth
characters (like Hiragana or Han Ideograph) occupy two columns per
character, and combining characters (apperaring in ISO-8859-11 Thai,
Unicode, and so on) occupy zero columns per character. mbwidth() gives the
width of the first character of the given string and mbswidth() gives the
width of the whole given string.

The names of mbwidth and mbswidth came from "multibyte" versions of wcwidth
and wcswidth which are "wide character" versions.

mblen(string) returns number of bytes of the first character of the string.
Please note that a character may consist of multiple bytes in multibyte
encodings such as UTF-8, EUC-JP, EUC-KR, GB2312, or Big5.

mbwidth(string) returns the width of the first character of the string.
mbswidth(string) returns the width of the whole string.

Parameters are to be given in locale encodings, not always in UTF-8.

WWW: http://search.cpan.org/dist/Text-CharWidth/