rigctl: 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/rigctl - from package: hamlib

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

On Debian possible default full paths are:

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

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

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