randtest: 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/randtest - from package: yagiuda

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