grib2scan: 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/grib2scan - from package: grads

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

On Debian possible default full paths are:

/usr/bin/grib2scan - from package: grads

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

Error in other languages:
grib2scan: bevel nie gevind nie
grib2scan: comandă negăsită
grib2scan: comando não encontrado
grib2scan: commande introuvable
grib2scan: command not found
grib2scan: käsku ei ole
grib2scan: không tìm thấy lệnh
grib2scan: komanda nerasta
grib2scan: Kommando nicht gefunden.
grib2scan: kommandot finns inte
grib2scan: komut yok
grib2scan: nie znaleziono polecenia
grib2scan: níor aimsíodh an t-ordú
grib2scan: no se encontró la orden
grib2scan: no s'ha trobat l'ordre
grib2scan: opdracht niet gevonden
grib2scan: parancs nem található
grib2scan: perintah tidak ditemukan
grib2scan: príkaz nenájdený
grib2scan: příkaz nenalezen
grib2scan: команда не найдена
grib2scan: командата не е открита
grib2scan: 命令找不到
grib2scan: コマンドが見つかりません