save2gdf: 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/save2gdf - from package: biosig-tools

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

Error in other languages:
save2gdf: bevel nie gevind nie
save2gdf: comandă negăsită
save2gdf: comando não encontrado
save2gdf: commande introuvable
save2gdf: command not found
save2gdf: käsku ei ole
save2gdf: không tìm thấy lệnh
save2gdf: komanda nerasta
save2gdf: Kommando nicht gefunden.
save2gdf: kommandot finns inte
save2gdf: komut yok
save2gdf: nie znaleziono polecenia
save2gdf: níor aimsíodh an t-ordú
save2gdf: no se encontró la orden
save2gdf: no s'ha trobat l'ordre
save2gdf: opdracht niet gevonden
save2gdf: parancs nem található
save2gdf: perintah tidak ditemukan
save2gdf: príkaz nenájdený
save2gdf: příkaz nenalezen
save2gdf: команда не найдена
save2gdf: командата не е открита
save2gdf: 命令找不到
save2gdf: コマンドが見つかりません