worker: 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/worker - from package: worker

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

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