gmtlogo: 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/gmtlogo - 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/gmtlogo - from package: GMT

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

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