gcstar: 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/gcstar - from package: gcstar

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