p++: 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/p++ - from package: pcc

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

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