sigul_server_add_admin: 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/sbin/sigul_server_add_admin - from package: sigul

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

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