oscilloscope: 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/oscilloscope - from package: oscilloscope

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

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