urdf_to_graphiz: command not found

Have You tried accessing the binary with the full path?

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/urdf_to_graphiz - from package: liburdfdom-tools

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