scanin: 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/scanin - from package: argyll

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

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