gate-in.exe: 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-in.exe - from package: GtkAda-devel

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

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