emu8051-cli: 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/emu8051-cli - from package: emu8051

You may install the required package with command apt-get install {package}
Error in other languages:
emu8051-cli: bevel nie gevind nie
emu8051-cli: comandă negăsită
emu8051-cli: comando não encontrado
emu8051-cli: commande introuvable
emu8051-cli: command not found
emu8051-cli: käsku ei ole
emu8051-cli: không tìm thấy lệnh
emu8051-cli: komanda nerasta
emu8051-cli: Kommando nicht gefunden.
emu8051-cli: kommandot finns inte
emu8051-cli: komut yok
emu8051-cli: nie znaleziono polecenia
emu8051-cli: níor aimsíodh an t-ordú
emu8051-cli: no se encontró la orden
emu8051-cli: no s'ha trobat l'ordre
emu8051-cli: opdracht niet gevonden
emu8051-cli: parancs nem található
emu8051-cli: perintah tidak ditemukan
emu8051-cli: príkaz nenájdený
emu8051-cli: příkaz nenalezen
emu8051-cli: команда не найдена
emu8051-cli: командата не е открита
emu8051-cli: 命令找不到
emu8051-cli: コマンドが見つかりません