shnstrip: 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/shnstrip - from package: shntool

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

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