addpix: 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/addpix - from package: wcstools

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

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