gfsplit: 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/gfsplit - from package: libgfshare-bin

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

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