dirvish: 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/dirvish - from package: dirvish

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

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