qsampler: 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/qsampler - from package: qsampler

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