idle3ctl: 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/sbin/idle3ctl - from package: idle3-tools

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

On Debian possible default full paths are:

/usr/sbin/idle3ctl - from package: idle3-tools

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

Error in other languages:
idle3ctl: bevel nie gevind nie
idle3ctl: comandă negăsită
idle3ctl: comando não encontrado
idle3ctl: commande introuvable
idle3ctl: command not found
idle3ctl: käsku ei ole
idle3ctl: không tìm thấy lệnh
idle3ctl: komanda nerasta
idle3ctl: Kommando nicht gefunden.
idle3ctl: kommandot finns inte
idle3ctl: komut yok
idle3ctl: nie znaleziono polecenia
idle3ctl: níor aimsíodh an t-ordú
idle3ctl: no se encontró la orden
idle3ctl: no s'ha trobat l'ordre
idle3ctl: opdracht niet gevonden
idle3ctl: parancs nem található
idle3ctl: perintah tidak ditemukan
idle3ctl: príkaz nenájdený
idle3ctl: příkaz nenalezen
idle3ctl: команда не найдена
idle3ctl: командата не е открита
idle3ctl: 命令找不到
idle3ctl: コマンドが見つかりません