Man pages matching name dirname in section 3:

dirName.3.en	debian 10 / libcdk5-dev
dirname.3.en	debian 10 / manpages-dev
dirname.3.es	debian 10 / manpages-es
dirname.3.ja	debian 10 / manpages-ja-dev
dirname.3.pl	debian 10 / manpages-pl-dev
dirName.3.en	debian 11 / libcdk5-dev
dirname.3.en	debian 11 / manpages-dev
dirname.3.es	debian 11 / manpages-es-dev
dirname.3.ja	debian 11 / manpages-ja-dev
dirname.3.pl	debian 11 / manpages-pl-dev
dirName.3.en	debian 12 / libcdk5-dev
dirname.3.en	debian 12 / manpages-dev
dirname.3.es	debian 12 / manpages-es-dev
dirname.3.fr	debian 12 / manpages-fr-dev
dirname.3.ja	debian 12 / manpages-ja-dev
dirname.3.pl	debian 12 / manpages-pl-dev
dirname.3.ru	debian 12 / manpages-ru-dev