rhost: 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/rhost - from package: jdresolve

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

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