kpeg: 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 Debian possible default full paths are:

/usr/bin/kpeg - from package: ruby-kpeg

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

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