xrotor: 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/xrotor - from package: xrotor

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

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