uhd_find_devices: 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 Debian possible default full paths are:

/usr/bin/uhd_find_devices - from package: uhd-host

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

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