hls: command not found

Have You tried accessing the binary with the full path?

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/hls - from package: hfsutils

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