rotctl: 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/rotctl - from package: hamlib

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/rotctl - from package: libhamlib-utils

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

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