fastjet-config: 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/fastjet-config - from package: libfastjet-dev

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

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