clang-3.5: 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/clang-3.5 - from package: clang-3.5

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

Error in other languages:
clang-3.5: bevel nie gevind nie
clang-3.5: comandă negăsită
clang-3.5: comando não encontrado
clang-3.5: commande introuvable
clang-3.5: command not found
clang-3.5: käsku ei ole
clang-3.5: không tìm thấy lệnh
clang-3.5: komanda nerasta
clang-3.5: Kommando nicht gefunden.
clang-3.5: kommandot finns inte
clang-3.5: komut yok
clang-3.5: nie znaleziono polecenia
clang-3.5: níor aimsíodh an t-ordú
clang-3.5: no se encontró la orden
clang-3.5: no s'ha trobat l'ordre
clang-3.5: opdracht niet gevonden
clang-3.5: parancs nem található
clang-3.5: perintah tidak ditemukan
clang-3.5: príkaz nenájdený
clang-3.5: příkaz nenalezen
clang-3.5: команда не найдена
clang-3.5: командата не е открита
clang-3.5: 命令找不到
clang-3.5: コマンドが見つかりません