mgd77track: 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/mgd77track - 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/mgd77track - from package: GMT

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

Error in other languages:
mgd77track: bevel nie gevind nie
mgd77track: comandă negăsită
mgd77track: comando não encontrado
mgd77track: commande introuvable
mgd77track: command not found
mgd77track: käsku ei ole
mgd77track: không tìm thấy lệnh
mgd77track: komanda nerasta
mgd77track: Kommando nicht gefunden.
mgd77track: kommandot finns inte
mgd77track: komut yok
mgd77track: nie znaleziono polecenia
mgd77track: níor aimsíodh an t-ordú
mgd77track: no se encontró la orden
mgd77track: no s'ha trobat l'ordre
mgd77track: opdracht niet gevonden
mgd77track: parancs nem található
mgd77track: perintah tidak ditemukan
mgd77track: príkaz nenájdený
mgd77track: příkaz nenalezen
mgd77track: команда не найдена
mgd77track: командата не е открита
mgd77track: 命令找不到
mgd77track: コマンドが見つかりません