expyriment-cli: 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/expyriment-cli - from package: python-expyriment

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

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