rcslpd: 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/rcslpd - from package: openslp-server

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

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