ann_sample: 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

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/ann_sample - from package: ann-tools

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