wavpack: 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/bin/wavpack - from package: wavpack

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

On Debian possible default full paths are:

/usr/bin/wavpack - from package: wavpack

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

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