ldapfinger: 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/sbin/ldapfinger - from package: ldapscripts

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