activemq: 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/activemq - from package: activemq

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

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