lpr: 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/lpr - from package: cups-bsd
/usr/bin/lpr - from package: lprng
/usr/bin/lpr - from package: lpr

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

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