xml2gv: 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/xml2gv - from package: ruby-graphviz

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

Error in other languages:
xml2gv: bevel nie gevind nie
xml2gv: comandă negăsită
xml2gv: comando não encontrado
xml2gv: commande introuvable
xml2gv: command not found
xml2gv: käsku ei ole
xml2gv: không tìm thấy lệnh
xml2gv: komanda nerasta
xml2gv: Kommando nicht gefunden.
xml2gv: kommandot finns inte
xml2gv: komut yok
xml2gv: nie znaleziono polecenia
xml2gv: níor aimsíodh an t-ordú
xml2gv: no se encontró la orden
xml2gv: no s'ha trobat l'ordre
xml2gv: opdracht niet gevonden
xml2gv: parancs nem található
xml2gv: perintah tidak ditemukan
xml2gv: príkaz nenájdený
xml2gv: příkaz nenalezen
xml2gv: команда не найдена
xml2gv: командата не е открита
xml2gv: 命令找不到
xml2gv: コマンドが見つかりません