shelr: 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/shelr - from package: shelr

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

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