glslparsertest: 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/glslparsertest - from package: piglit

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

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