grfstrip: 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/grfstrip - from package: grfcodec

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