gmtpath: 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/gmtpath - 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/gmtpath - from package: GMT

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

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