fcheck: 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/sbin/fcheck - from package: fcheck

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

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