rasls: 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/rasls - from package: ncl

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

On Debian possible default full paths are:

/usr/bin/rasls - from package: ncl-ncarg

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

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