cleo: 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 Debian possible default full paths are:

/usr/bin/cleo - from package: cleo

You may install the required package with command apt-get install {package}

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