e3ws: command not found

Have You tried accessing the binary with the full path?

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/e3ws - from package: e3

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

On Debian possible default full paths are:

/usr/bin/e3ws - from package: e3

You may install the required package with command apt-get install {package}
Error in other languages:
e3ws: bevel nie gevind nie
e3ws: comandă negăsită
e3ws: comando não encontrado
e3ws: commande introuvable
e3ws: command not found
e3ws: käsku ei ole
e3ws: không tìm thấy lệnh
e3ws: komanda nerasta
e3ws: Kommando nicht gefunden.
e3ws: kommandot finns inte
e3ws: komut yok
e3ws: nie znaleziono polecenia
e3ws: níor aimsíodh an t-ordú
e3ws: no se encontró la orden
e3ws: no s'ha trobat l'ordre
e3ws: opdracht niet gevonden
e3ws: parancs nem található
e3ws: perintah tidak ditemukan
e3ws: príkaz nenájdený
e3ws: příkaz nenalezen
e3ws: команда не найдена
e3ws: командата не е открита
e3ws: 命令找不到
e3ws: コマンドが見つかりません