hciconfig: 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/sbin/hciconfig - from package: bluez

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

On Debian possible default full paths are:

/bin/hciconfig - from package: bluez

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

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