btag: 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 Debian possible default full paths are:

/usr/bin/btag - from package: btag

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

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