loki: command not found

Have You tried accessing the binary with the full path?

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/loki - from package: loki

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