slapindex: 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/slapindex - from package: openldap-servers

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

On Debian possible default full paths are:

/usr/sbin/slapindex - from package: slapd

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

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