gps2udp: command not found

Have You tried accessing the binary with the full path?

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/gps2udp - from package: gpsd-clients

You may install the required package with command apt-get install {package}
Error in other languages:
gps2udp: bevel nie gevind nie
gps2udp: comandă negăsită
gps2udp: comando não encontrado
gps2udp: commande introuvable
gps2udp: command not found
gps2udp: käsku ei ole
gps2udp: không tìm thấy lệnh
gps2udp: komanda nerasta
gps2udp: Kommando nicht gefunden.
gps2udp: kommandot finns inte
gps2udp: komut yok
gps2udp: nie znaleziono polecenia
gps2udp: níor aimsíodh an t-ordú
gps2udp: no se encontró la orden
gps2udp: no s'ha trobat l'ordre
gps2udp: opdracht niet gevonden
gps2udp: parancs nem található
gps2udp: perintah tidak ditemukan
gps2udp: príkaz nenájdený
gps2udp: příkaz nenalezen
gps2udp: команда не найдена
gps2udp: командата не е открита
gps2udp: 命令找不到
gps2udp: コマンドが見つかりません