ptrash: 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/ptrash - from package: ptrash

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

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