gcat: 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/gcat - from package: onioncat

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

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