xttpd: 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
/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/sbin/xttpd - from package: xtide

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