taucxx: 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/taucxx - from package: tau
/usr/lib/tau/x86_64/bin/taucxx - from package: tau

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

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