tau2cube: 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/tau2cube - from package: cube

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

Error in other languages:
tau2cube: bevel nie gevind nie
tau2cube: comandă negăsită
tau2cube: comando não encontrado
tau2cube: commande introuvable
tau2cube: command not found
tau2cube: käsku ei ole
tau2cube: không tìm thấy lệnh
tau2cube: komanda nerasta
tau2cube: Kommando nicht gefunden.
tau2cube: kommandot finns inte
tau2cube: komut yok
tau2cube: nie znaleziono polecenia
tau2cube: níor aimsíodh an t-ordú
tau2cube: no se encontró la orden
tau2cube: no s'ha trobat l'ordre
tau2cube: opdracht niet gevonden
tau2cube: parancs nem található
tau2cube: perintah tidak ditemukan
tau2cube: príkaz nenájdený
tau2cube: příkaz nenalezen
tau2cube: команда не найдена
tau2cube: командата не е открита
tau2cube: 命令找不到
tau2cube: コマンドが見つかりません