itstool: 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/itstool - from package: itstool

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

On Debian possible default full paths are:

/usr/bin/itstool - from package: itstool

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

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