geistest: 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/geistest - from package: geis-tools

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

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