esfilter: 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/esfilter - from package: tstools

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

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