bleygraph: 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/bleygraph - from package: bley

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

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