tucd: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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/tucd - from package: tcm

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