slapauth: 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/slapauth - from package: openldap-servers

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

On Debian possible default full paths are:

/usr/sbin/slapauth - from package: slapd

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

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