gcc34: 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/gcc34 - from package: compat-gcc-34

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

Error in other languages:
gcc34: bevel nie gevind nie
gcc34: comandă negăsită
gcc34: comando não encontrado
gcc34: commande introuvable
gcc34: command not found
gcc34: käsku ei ole
gcc34: không tìm thấy lệnh
gcc34: komanda nerasta
gcc34: Kommando nicht gefunden.
gcc34: kommandot finns inte
gcc34: komut yok
gcc34: nie znaleziono polecenia
gcc34: níor aimsíodh an t-ordú
gcc34: no se encontró la orden
gcc34: no s'ha trobat l'ordre
gcc34: opdracht niet gevonden
gcc34: parancs nem található
gcc34: perintah tidak ditemukan
gcc34: príkaz nenájdený
gcc34: příkaz nenalezen
gcc34: команда не найдена
gcc34: командата не е открита
gcc34: 命令找不到
gcc34: コマンドが見つかりません