glx-dont-care-mask: 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/lib64/piglit/bin/glx-dont-care-mask - from package: piglit

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

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