grc: 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/grc - from package: grc

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