gate: 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 CentOS possible default full paths are:

/usr/bin/gate - from package: GtkAda-devel

You may install the required package with command yum install {package}

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