buddy-ng: command not found

Have You tried accessing the binary with the full path?

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/buddy-ng - from package: aircrack-ng

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