gcap: 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/gcap - from package: gcap

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

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