grdview: 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/grdview - from package: GMT

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

On Debian possible default full paths are:

/usr/lib/gmt/bin/grdview - from package: GMT

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

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