ttywatch: 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/ttywatch - from package: ttywatch

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

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