indextool: 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/indextool - from package: sphinx

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

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