rsearch: 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/rsearch - from package: 389-ds-base

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

On Debian possible default full paths are:

/usr/bin/rsearch - from package: 389-ds-base

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

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