gpiv: 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 - from package: gpiv-mpi
/usr/bin/gpiv - from package: gpiv

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

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