aatest: 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 CentOS possible default full paths are:

/usr/bin/aatest - from package: aalib

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/aatest - from package: libaa-bin

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

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