hwstamp_ctl: 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/hwstamp_ctl - from package: linuxptp

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

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