avg_showfont: 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/avg_showfont - from package: python-libavg

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

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