piglit-run: 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/piglit-run - from package: piglit

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

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