rougify: 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 Debian possible default full paths are:

/usr/bin/rougify - from package: ruby-rouge

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