xmltest: 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/xmltest - from package: sblim-sfcb

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

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