privoxy: 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 CentOS possible default full paths are:

/usr/sbin/privoxy - from package: privoxy

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/sbin/privoxy - from package: privoxy

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

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