dpigs: 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/dpigs - from package: debian-goodies

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

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