tty: 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/tty - from package: coreutils

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

On Debian possible default full paths are:

/usr/bin/tty - from package: coreutils

You may install the required package with command apt-get install {package}

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