gpiv_fft: 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/gpiv_fft - from package: gpivtools-mpi
/usr/bin/gpiv_fft - from package: gpivtools

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

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