cdk5-config: 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/cdk5-config - from package: cdk-devel

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

Error in other languages:
cdk5-config: bevel nie gevind nie
cdk5-config: comandă negăsită
cdk5-config: comando não encontrado
cdk5-config: commande introuvable
cdk5-config: command not found
cdk5-config: käsku ei ole
cdk5-config: không tìm thấy lệnh
cdk5-config: komanda nerasta
cdk5-config: Kommando nicht gefunden.
cdk5-config: kommandot finns inte
cdk5-config: komut yok
cdk5-config: nie znaleziono polecenia
cdk5-config: níor aimsíodh an t-ordú
cdk5-config: no se encontró la orden
cdk5-config: no s'ha trobat l'ordre
cdk5-config: opdracht niet gevonden
cdk5-config: parancs nem található
cdk5-config: perintah tidak ditemukan
cdk5-config: príkaz nenájdený
cdk5-config: příkaz nenalezen
cdk5-config: команда не найдена
cdk5-config: командата не е открита
cdk5-config: 命令找不到
cdk5-config: コマンドが見つかりません