grig: 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/grig - from package: grig

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