apt-file: 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/apt-file - from package: apt-file

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

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