esperanza: 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/esperanza - from package: esperanza

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