estwaver: 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/estwaver - from package: hyperestraier

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

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