ppodchecker: command not found

Have You tried accessing the binary with the full path?

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/ppodchecker - from package: perl-Pod-PseudoPod

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