astext: 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/astext - from package: libAfterImage-devel

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

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