euca-revoke: 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/euca-revoke - from package: euca2ools

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

On Debian possible default full paths are:

/usr/bin/euca-revoke - from package: euca2ools

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