expectk: 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/expectk - from package: expectk

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

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