omniidl: 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/omniidl - from package: omniORB-devel

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

On Debian possible default full paths are:

/usr/bin/omniidl - from package: omniidl

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

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