esreverse: 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/esreverse - from package: tstools

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

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