gsdj500: 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/gsdj500 - from package: ghostscript

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

On Debian possible default full paths are:

/usr/bin/gsdj500 - from package: ghostscript

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

Error in other languages:
gsdj500: bevel nie gevind nie
gsdj500: comandă negăsită
gsdj500: comando não encontrado
gsdj500: commande introuvable
gsdj500: command not found
gsdj500: käsku ei ole
gsdj500: không tìm thấy lệnh
gsdj500: komanda nerasta
gsdj500: Kommando nicht gefunden.
gsdj500: kommandot finns inte
gsdj500: komut yok
gsdj500: nie znaleziono polecenia
gsdj500: níor aimsíodh an t-ordú
gsdj500: no se encontró la orden
gsdj500: no s'ha trobat l'ordre
gsdj500: opdracht niet gevonden
gsdj500: parancs nem található
gsdj500: perintah tidak ditemukan
gsdj500: príkaz nenájdený
gsdj500: příkaz nenalezen
gsdj500: команда не найдена
gsdj500: командата не е открита
gsdj500: 命令找不到
gsdj500: コマンドが見つかりません