dgc: 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 CentOS possible default full paths are:

/usr/bin/dgc - from package: dgc

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