lrcalc: 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/lrcalc - from package: lrcalc

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

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