This function together with the pam_set_data(3) function is useful to manage module-specific data meaningful only to the calling PAM module.
The pam_get_data function
      looks up the object associated with the (hopefully) unique
      string module_data_name in the PAM
      context specified by the pamh argument. A successful call
      to pam_get_data will result in
      data pointing to the
      object. Note, this data is not a copy and should be treated
      as constant by the
      module.
Data was successful retrieved.
A NULL pointer was submitted as PAM handle or the function was called by an application.
Module data not found or there is an entry, but it has the value NULL.
pam_end(3), pam_set_data(3), pam_strerror(3)
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                  See Linux-PAM copyright notice for more information.
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