frend: 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/frend - from package: libbio-graphics-perl

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

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