sndfile-jackplay: 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/sndfile-jackplay - from package: sndfile-tools

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

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