mao:~# whereis vi
vi: /usr/bin/vi /usr/share/vi /usr/share/man/man1/vi.1.gz
mao:~# whereis man
man: /usr/bin/man /usr/local/man /usr/share/man /usr/share/man/man1/man.1.gz /usr/share/man/man7/man.7.gz
mao:~# whereis yes
yes: /usr/bin/yes /usr/share/man/man1/yes.1.gz
mao:~# whereis echo
echo: /bin/echo /usr/share/man/man1/echo.1.gz
mao:~# whereis less
less: /usr/bin/less /usr/share/man/man1/less.1.gz
mao:~# whereis fcitx
fcitx: /usr/bin/fcitx /usr/share/fcitx
谁用谁知道:)