avg_showsvg: 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/avg_showsvg - from package: python-libavg

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