EnumPrinters

The EnumPrinters function enumerates available printers, print servers, domains, or print providers.

BOOL EnumPrinters(

Parameters

Flags

Specifies the types of print objects that the function should enumerate. This value can be a combination of the following constants:

If Level is 4, you can only use the PRINTER_ENUM_CONNECTIONS and PRINTER_ENUM_LOCAL constants.

Name

If Level is 1, Flags contains PRINTER_ENUM_NAME, and Name is non-NULL, Name points to a null-terminated string that specifies the name of the object to enumerate. This string can be the name of a server, a domain, or a print provider.

If Level is 1, Flags contains PRINTER_ENUM_NAME, and Name is NULL, the function enumerates the available print providers.

If Level is 1, Flags contains PRINTER_ENUM_REMOTE, and Name is NULL, the function enumerates the printers in the user's domain.

If Level is 2 or 5, Name points to a null-terminated string that specifies the name of a server whose printers are to be enumerated. If this string is NULL, the function enumerates the printers installed on the local machine.

If Level is 4, Name should be NULL. The function always queries on the local machine.

When Name is NULL, it enumerates printers that are installed on the local machine. These printers include those that are physically attached to the local machine as well as remote printers to which it has a network connection.

Level

Specifies the type of data structures pointed to by pPrinterEnum. Valid values are 1, 2, 4, and 5, which correspond to the PRINTER_INFO_1, PRINTER_INFO_2, PRINTER_INFO_4, and PRINTER_INFO_5 data structures.

Windows 95: The value can be 1, 2, or 5.

Windows NT: This value can be 1, 2, 4, or 5.

pPrinterEnum

Pointer to a buffer that receives an array of PRINTER_INFO_1, PRINTER_INFO_2, PRINTER_INFO_4, or PRINTER_INFO_5 structures. Each structure contains data that describes an available print object. If Level is 1, the array contains PRINTER_INFO_1 structures. If Level is 2, the array contains PRINTER_INFO_2 structures. If Level is 4, the array contains PRINTER_INFO_4 structures. If Level is 5, the array contains PRINTER_INFO_5 structures.

Windows 95: The buffer cannot receive PRINTER_INFO_4 structures. It can receive any of the other types.

cbBuf

Specifies the size, in bytes, of the array pointed to by pPrinterEnum.

pcbNeeded

Pointer to a value that receives the number of bytes copied if the function succeeds or the number of bytes required if cbBuf is too small.

pcReturned

Pointer to a value that receives the number of PRINTER_INFO_1, PRINTER_INFO_2, PRINTER_INFO_4, or PRINTER_INFO_5 structures that the function returns in the array to which pPrinterEnum points.

Return Values

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

If EnumPrinters returns a PRINTER_INFO_1 structure in which PRINTER_ENUM_CONTAINER is specified, this indicates that there is a hierarchy of printer objects. An application can enumerate the hierarchy by calling EnumPrinters again, setting Name to the value of the PRINTER_INFO_1 structure's pName member.

The EnumPrinters function does not retrieve security information. If PRINTER_INFO_2 structures are returned in the array pointed to by pPrinterEnum, their pSecurityDescriptor members will be set to NULL.

To get information about the default printer, call the GetProfileString function with the section name string set to "windows" and the key name string set to "device". The returned string contains the name of the default printer, the name of the printer DRV file, and the port to which the printer is attached.

Windows NT:

The PRINTER_INFO_4 structure provides an easy and extremely fast way to retrieve the names of the printers installed on a local machine, as well as the remote connections that a user has established. When EnumPrinters is called with a PRINTER_INFO_4 data structure, that function queries the registry for the specified information, then returns immediately. This differs from the behavior of EnumPrinters when called with other levels of PRINTER_INFO_* data structures. In particular, when EnumPrinters is called with a level 2 (PRINTER_INFO_2) data structure, it performs an OpenPrinter call on each remote connection. If a remote connection is down, or the remote server no longer exists, or the remote printer no longer exists, the function must wait for RPC to time out and consequently fail the OpenPrinter call. This can take a while. Passing a PRINTER_INFO_4 structure lets an application retrieve a bare minimium of required information; if more detailed information is desired, a subsequent EnumPrinter level 2 call can be made.

Windows 95:

To quickly enumerate local and network printers, use the PRINTER_INFO_5 structure. This causes EnumPrinters to query the registry rather than make remote calls, and is similar to using the PRINTER_INFO_4 structure on Windows NT as described in the preceding paragraph.

Examples

The following table shows the EnumPrinters output for various Flags values when the Level parameter is set to 1.

In the Name parameter column of the table, you should substitute an appropriate name for Print Provider, Domain, and Machine. For example, for Print Provider, you could use the name of the Windows NT network print provider: "Windows NT Remote Printers", or the name of the Windows 95 local print provider: "Windows 95 Local Print Provider". To get print provider names, call EnumPrinters with Name set to NULL.

See Also

AddPrinter, DeletePrinter, GetPrinter, GetProfileString, PRINTER_INFO_1, PRINTER_INFO_2, PRINTER_INFO_4, PRINTER_INFO_5, SetPrinter