xdeview: 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 Debian possible default full paths are:

/usr/bin/xdeview - from package: xdeview

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

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