gdis: 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/gdis - from package: gdis

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