lemonldap-ng-cli: command not found

Have You tried accessing the binary with the full path?

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 Debian possible default full paths are:

/usr/bin/lemonldap-ng-cli - from package: liblemonldap-ng-cli-perl
/usr/share/lemonldap-ng/bin/lemonldap-ng-cli - from package: liblemonldap-ng-manager-perl

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