issndfile: 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/issndfile - from package: nas

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

On Debian possible default full paths are:

/usr/bin/issndfile - from package: nas-bin

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

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