shncmp: 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/shncmp - from package: shntool

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

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