qtoctave_pkg: 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/qtoctave_pkg - from package: qtoctave

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

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