ansifilter-gui: 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/ansifilter-gui - from package: ansifilter-gui

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

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