erb: 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/erb - from package: ruby

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

On Debian possible default full paths are:

/usr/bin/erb - from package: ruby
/usr/lib/ruby-standalone/bin/erb - from package: ruby-standalone

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

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