GET: 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 CentOS possible default full paths are:

/usr/bin/GET - from package: perl-libwww-perl

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/GET - from package: libwww-perl

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

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