dmxinfo: 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/dmxinfo - from package: xorg-x11-server-Xdmx

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

On Debian possible default full paths are:

/usr/bin/dmxinfo - from package: xdmx-tools

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

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