hdhomerun_config: 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/hdhomerun_config - from package: hdhomerun

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

On Debian possible default full paths are:

/usr/bin/hdhomerun_config - from package: hdhomerun-config

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

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