EnumPorts function

Article
01/07/2021

The EnumPorts function enumerates the ports that are available for printing on a specified server.

Syntax

BOOL EnumPorts(
  _In_  LPTSTR  pName,
  _In_  DWORD   Level,
  _Out_ LPBYTE  pPorts,
  _In_  DWORD   cbBuf,
  _Out_ LPDWORD pcbNeeded,
  _Out_ LPDWORD pcReturned
);

Parameters

pName [in]

A pointer to a null-terminated string that specifies the name of the server whose printer ports you want to enumerate.

If pName is NULL, the function enumerates the local machine's printer ports.

Level [in]

The type of information returned in the pPorts buffer. If Level is 1, pPorts receives an array of PORT_INFO_1 structures. If Level is 2, pPorts receives an array of PORT_INFO_2 structures.

pPorts [out]

A pointer to a buffer that receives an array of PORT_INFO_1 or PORT_INFO_2 structures. Each structure contains data that describes an available printer port. The buffer must be large enough to store the strings pointed to by the structure members.

To determine the required buffer size, call EnumPorts with cbBuf set to zero. EnumPorts fails, GetLastError returns ERROR_INSUFFICIENT_BUFFER, and the pcbNeeded parameter returns the size, in bytes, of the buffer required to hold the array of structures and their data.

cbBuf [in]

The size, in bytes, of the buffer pointed to by pPorts.

pcbNeeded [out]

A pointer to a variable that receives the number of bytes copied to the pPorts buffer. If the buffer is too small, the function fails and the variable receives the number of bytes required.

pcReturned [out]

A pointer to a variable that receives the number of PORT_INFO_1 or PORT_INFO_2 structures returned in the pPorts buffer. This is the number of printer ports that are available on the specified server.

Return value

If the function succeeds, the return value is a nonzero value.

If the function fails, the return value is zero.

Remarks

Note

This is a blocking or synchronous function and might not return immediately. How quickly this function returns depends on run-time factors such as network status, print server configuration, and printer driver implementation factors that are difficult to predict when writing an application. Calling this function from a thread that manages interaction with the user interface could make the application appear to be unresponsive.

The EnumPorts function can succeed even if the server specified by pName does not have a printer defined.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Header	Winspool.h (include Windows.h)
Library	Winspool.lib
DLL	Winspool.drv
Unicode and ANSI names	EnumPortsW (Unicode) and EnumPortsA (ANSI)