tfdocgen: 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/tfdocgen - from package: tfdocgen

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

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