catdvi: 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/catdvi - from package: catdvi

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

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