fatsend: 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/fatsend - from package: cernlib-packlib

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

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