pure-ftpd-ldap: 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 Debian possible default full paths are:

/usr/sbin/pure-ftpd-ldap - from package: pure-ftpd-ldap

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

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