rarian-sk-update: 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 CentOS possible default full paths are:

/usr/bin/rarian-sk-update - from package: rarian-compat

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/rarian-sk-update - from package: rarian-compat

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

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