rahosts: 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/bin/rahosts - from package: argus-client

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