rec_control: 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/rec_control - from package: pdns-recursor

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

On Debian possible default full paths are:

/usr/bin/rec_control - from package: pdns-recursor

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

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