kolf: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/kolf - from package: kdegames

You may install the required package with command yum install {package}

Error in other languages:
kolf: bevel nie gevind nie
kolf: comandă negăsită
kolf: comando não encontrado
kolf: commande introuvable
kolf: command not found
kolf: käsku ei ole
kolf: không tìm thấy lệnh
kolf: komanda nerasta
kolf: Kommando nicht gefunden.
kolf: kommandot finns inte
kolf: komut yok
kolf: nie znaleziono polecenia
kolf: níor aimsíodh an t-ordú
kolf: no se encontró la orden
kolf: no s'ha trobat l'ordre
kolf: opdracht niet gevonden
kolf: parancs nem található
kolf: perintah tidak ditemukan
kolf: príkaz nenájdený
kolf: příkaz nenalezen
kolf: команда не найдена
kolf: командата не е открита
kolf: 命令找不到
kolf: コマンドが見つかりません