lgrep: 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/lgrep - from package: lv

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

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