linux man page for pam_get_user

PAM_GET_USER(3) 						 Linux-PAM Manual						   PAM_GET_USER(3)

NAME
       pam_get_user - get user name

SYNOPSIS
       #include <security/pam_modules.h>

       int pam_get_user(const pam_handle_t *pamh, const char **user, const char *prompt);

DESCRIPTION
       The pam_get_user function returns the name of the user specified by pam_start(3). If no user was specified it what pam_get_item (pamh,
       PAM_USER, ... ); would have returned. If this is NULL it obtains the username via the pam_conv(3) mechanism, it prompts the user with the
       first non-NULL string in the following list:

       o   The prompt argument passed to the function.

       o   What is returned by pam_get_item (pamh, PAM_USER_PROMPT, ... );

       o   The default prompt: "login: "

       By whatever means the username is obtained, a pointer to it is returned as the contents of *user. Note, this memory should not be free()'d
       or modified by the module.

       This function sets the PAM_USER item associated with the pam_set_item(3) and pam_get_item(3) functions.

RETURN VALUES
       PAM_SUCCESS
	   User name was successful retrieved.

       PAM_SYSTEM_ERR
	   A NULL pointer was submitted.

       PAM_CONV_ERR
	   The conversation method supplied by the application failed to obtain the username.

SEE ALSO
       pam_end(3), pam_get_item(3), pam_set_item(3), pam_strerror(3)

Linux-PAM Manual						    06/04/2011							   PAM_GET_USER(3)