grcat: 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/grcat - from package: grc

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

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