iwevent: 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:

/sbin/iwevent - from package: wireless-tools

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

On Debian possible default full paths are:

/sbin/iwevent - from package: wireless-tools

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

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