3 which "$1" >/dev/null 2>&1
7 if available update-mime-database
9 update-mime-database /usr/share/mime >/dev/null
12 if available update-desktop-database
14 update-desktop-database -q /usr/share/applications
17 if available gtk-update-icon-cache
19 gtk-update-icon-cache -q /usr/share/icons/hicolor