sndfile-cmp: 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/sndfile-cmp - from package: libsndfile

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

On Debian possible default full paths are:

/usr/bin/sndfile-cmp - from package: sndfile-programs

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

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