withlock: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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/withlock - from package: withlock

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