Gemalto Prox–DU Guide

PC/SC Guide
Prox–DU & Prox–SU
www.gemalto.com
DOC119811A Public Use Page 26/129
SCardListReaders Function
The SCardListReaders function provides the list of readers within a set of named reader
groups, eliminating duplicates.
The caller supplies a list of reader groups, and receives the list of readers within the named
groups. Unrecognized group names are ignored.
Syntax:
LONG WINAPI SCardListReaders(
__in SCARDCONTEXT hContext,
__in_opt LPCTSTR mszGroups,
__out LPTSTR mszReaders,
__inout LPDWORD pcchReaders
);
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 [in, optional]
Names of the reader groups defined to the system, as a multi-string. Use a NULL
value to list all readers in the system (that is, the SCard$AllReaders group).
mszReaders [out]
Multi-string that lists the card readers within the supplied reader groups. If this value
is NULL, SCardListReaders ignores the buffer length supplied in pcchReaders,
writes the length of the buffer that would have been returned if this parameter had
not been NULL to pcchReaders, and returns a success code.
pcchReaders [in, out]
Length of the mszReaders buffer in characters. This parameter receives the actual
length of the multi-string structure, including all trailing null characters. If the buffer
length is specified as SCARD_AUTOALLOCATE, then mszReaders 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.
Group contains no readers: SCARD_E_NO_READERS_AVAILABLE
Other: An error code. For more information, see Smart Card Return Values.
Remarks:
The SCardListReaders 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 readers.

Gemalto Prox–DU Specifications

General

Brand	Gemalto
Model	Prox–DU
Category	Card Reader
Language	English