rigmem: 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/rigmem - from package: hamlib

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

On Debian possible default full paths are:

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

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

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