glade-3: 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/glade-3 - from package: glade3

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

Error in other languages:
glade-3: bevel nie gevind nie
glade-3: comandă negăsită
glade-3: comando não encontrado
glade-3: commande introuvable
glade-3: command not found
glade-3: käsku ei ole
glade-3: không tìm thấy lệnh
glade-3: komanda nerasta
glade-3: Kommando nicht gefunden.
glade-3: kommandot finns inte
glade-3: komut yok
glade-3: nie znaleziono polecenia
glade-3: níor aimsíodh an t-ordú
glade-3: no se encontró la orden
glade-3: no s'ha trobat l'ordre
glade-3: opdracht niet gevonden
glade-3: parancs nem található
glade-3: perintah tidak ditemukan
glade-3: príkaz nenájdený
glade-3: příkaz nenalezen
glade-3: команда не найдена
glade-3: командата не е открита
glade-3: 命令找不到
glade-3: コマンドが見つかりません