dansguardian: 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/sbin/dansguardian - from package: dansguardian

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

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