astyle: 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/astyle - from package: astyle

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

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