ifdhandler: 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/sbin/ifdhandler - from package: openct

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

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