bti: 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/bti - from package: bti

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

On Debian possible default full paths are:

/usr/bin/bti - from package: bti

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

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