euare-userlistkeys: 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 CentOS possible default full paths are:

/usr/bin/euare-userlistkeys - from package: euca2ools

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/euare-userlistkeys - from package: euca2ools

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