ptar: 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/ptar - from package: perl-Archive-Tar

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

On Debian possible default full paths are:

/usr/bin/ptar - from package: perl

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

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