functest: 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 CentOS possible default full paths are:

/usr/bin/functest - from package: python-functest

You may install the required package with command yum install {package}

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