ooimpress: 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/ooimpress - from package: libreoffice-impress

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

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