История изменений

Не помню, где и когда я их надыбал. Вот тебе выписка из мана:

There are two special cases** of bracket expressions: the bracket
expressions ‘[[:<:]]’ and ‘[[:>:]]’ match the null string at the
beginning and end of a word, respectively.  A word is defined as a
sequence of characters starting and ending with a word character which is
neither preceded nor followed by word characters.  A word character is an
alnum character (as defined by isalnum(3)) or an underscore.  This is an
extension, compatible with but not specified by POSIX, and should be used
with caution in software intended to be portable to other systems.  The
additional word delimiters ‘\<’ and ‘\>’ are provided to ease
compatibility with traditional SVR4 systems but are not portable and
should be avoided.

ref: http://mdoc.su/o/re_format

Т.ч. кошернее их заменить на [[:<:]] и [[:>:]], но это на 5 символов больше. ;) Ещё можно использовать \b.

UPD: гуглить по regex word boundary

Не помню, где и когда я их надыбал. Вот тебе выписка из мана:

There are two special cases** of bracket expressions: the bracket
expressions ‘[[:<:]]’ and ‘[[:>:]]’ match the null string at the
beginning and end of a word, respectively.  A word is defined as a
sequence of characters starting and ending with a word character which is
neither preceded nor followed by word characters.  A word character is an
alnum character (as defined by isalnum(3)) or an underscore.  This is an
extension, compatible with but not specified by POSIX, and should be used
with caution in software intended to be portable to other systems.  The
additional word delimiters ‘\<’ and ‘\>’ are provided to ease
compatibility with traditional SVR4 systems but are not portable and
should be avoided.

ref: http://mdoc.su/o/re_format

Т.ч. кошернее их заменить на [[:<:]] и [[:>:]], но это на 5 символов больше. ;) Ещё можно использовать \b.