pxdvi-xaw3d: 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/pxdvi-xaw3d - from package: xdvik

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

Error in other languages:
pxdvi-xaw3d: bevel nie gevind nie
pxdvi-xaw3d: comandă negăsită
pxdvi-xaw3d: comando não encontrado
pxdvi-xaw3d: commande introuvable
pxdvi-xaw3d: command not found
pxdvi-xaw3d: käsku ei ole
pxdvi-xaw3d: không tìm thấy lệnh
pxdvi-xaw3d: komanda nerasta
pxdvi-xaw3d: Kommando nicht gefunden.
pxdvi-xaw3d: kommandot finns inte
pxdvi-xaw3d: komut yok
pxdvi-xaw3d: nie znaleziono polecenia
pxdvi-xaw3d: níor aimsíodh an t-ordú
pxdvi-xaw3d: no se encontró la orden
pxdvi-xaw3d: no s'ha trobat l'ordre
pxdvi-xaw3d: opdracht niet gevonden
pxdvi-xaw3d: parancs nem található
pxdvi-xaw3d: perintah tidak ditemukan
pxdvi-xaw3d: príkaz nenájdený
pxdvi-xaw3d: příkaz nenalezen
pxdvi-xaw3d: команда не найдена
pxdvi-xaw3d: командата не е открита
pxdvi-xaw3d: 命令找不到
pxdvi-xaw3d: コマンドが見つかりません