line: 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/line - from package: util-linux

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

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