supervisorctl: 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/supervisorctl - from package: supervisor

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

On Debian possible default full paths are:

/usr/bin/supervisorctl - from package: supervisor

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

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