penlog: 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/penlog - from package: pen

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

On Debian possible default full paths are:

/usr/bin/penlog - from package: pen

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

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