gdc: 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/gdc - from package: perl-WWW-GoodData

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

On Debian possible default full paths are:

/usr/bin/gdc - from package: gdc

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

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