update-inetd: 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/sbin/update-inetd - from package: rlinetd
/usr/sbin/update-inetd - from package: update-inetd

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

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