Виджеты KDE Plasma5 по умолчанию

Чтобы расширить идеальный ответ Джиммиджа:

shopt -s extglob

Загружается расширенное сопоставление с образцом в bash. Изman bash:

If the extglob shell option is enabled using the shopt builtin, several
extended pattern matching operators are recognized.  In  the  following
description, a pattern-list is a list of one or more patterns separated
by a |.  Composite patterns may be formed using  one  or  more  of  the
following sub-patterns:

      ?(pattern-list)
             Matches zero or one occurrence of the given patterns
      *(pattern-list)
             Matches zero or more occurrences of the given patterns
      +(pattern-list)
             Matches one or more occurrences of the given patterns
      @(pattern-list)
             Matches one of the given patterns
      !(pattern-list)
             Matches anything except one of the given patterns

Поэтому:

rm -rfvi./!(build)

Оценивается как удаление всего, кроме данного шаблона.