apt-grip: 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/sbin/apt-grip - from package: emdebian-grip

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

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