grdrotater: 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/grdrotater - 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/grdrotater - from package: GMT

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

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