oggCat: 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/oggCat - from package: oggvideotools

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

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