hotspotter: 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/hotspotter - 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/hotspotter - from package: GMT

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

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