categories: 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/lib/fastdnaml/bin/categories - from package: fastdnaml

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

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