xpans: 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/xpans - from package: xpa

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

On Debian possible default full paths are:

/usr/bin/xpans - from package: xpa-tools

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

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