rotconverter: 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/rotconverter - 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/rotconverter - from package: GMT

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

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