shotdetect: 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/shotdetect - from package: shotdetect

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

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