gnatfind: 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/gnatfind - from package: gcc-gnat

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

On Debian possible default full paths are:

/usr/bin/gnatfind - from package: gnat-4.9

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

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