slxdecode: 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/slxdecode - from package: printer-driver-foo2zjs

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

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