bbdigest: 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/xymon/server/bin/bbdigest - from package: xymon

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

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