Gemalto Prox–DU Guide

PC/SC Guide
Prox–DU & Prox–SU
www.gemalto.com
DOC119811A Public Use Page 24/129
SCardListReaderGroups Function
The SCardListReaderGroups function provides the list of reader groups that have previously
been introduced to the system.
Syntax:
LONG WINAPI SCardListReaderGroups(
__in SCARDCONTEXT hContext,
__out LPTSTR mszGroups,
__inout LPDWORD pcchGroups
);
Parameters:
hContext [in]
Handle that identifies the resource manager context for the query. The resource
manager context can be set by a previous call to SCardEstablishContext. This
parameter cannot be NULL.
mszGroups [out]
Multi-string that lists the reader groups defined to the system and available to the
current user on the current terminal. If this value is NULL, SCardListReaderGroups
ignores the buffer length supplied in pcchGroups, writes the length of the buffer that
would have been returned if this parameter had not been NULL to pcchGroups, and
returns a success code.
pcchGroups [in, out]
Length of the mszGroups buffer in characters, and receives the actual length of the
multi-string structure, including all trailing null characters. If the buffer length is
specified as SCARD_AUTOALLOCATE, then mszGroups is converted to a pointer
to a byte pointer, and receives the address of a block of memory containing the
multi-string structure. This block of memory must be deallocated with
SCardFreeMemory.
Return Value:
This function returns different values depending on whether it succeeds or fails:
Success: SCARD_S_SUCCESS.
Failure: An error code. For more information, see Smart Card Return Values.
Remarks:
A group is returned only if it contains at least one reader. This includes the group
SCard$DefaultReaders. The group SCard$AllReaders cannot be returned, since it only
exists implicitly.
The SCardListReaderGroups function is a database query function. For more information on
other database query functions, see Smart Card Database Query Functions.
Examples:
The following example shows listing the reader groups.
LPTSTR pmszReaderGroups = NULL;
LPTSTR pReaderGroup;
LONG lReturn;

Gemalto Prox–DU Specifications

General

Brand	Gemalto
Model	Prox–DU
Category	Card Reader
Language	English