myproxy-get.pl: 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/myproxy-get.pl - from package: perl-VOMS-Lite

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

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