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ComDBClaimPort function (msports.h)

ComDBClaimPort logs an unused COM port number as "in use" in the COM port database.

Syntax

LONG ComDBClaimPort(
  [in]            HCOMDB HComDB,
  [in]            DWORD  ComNumber,
  [in]            BOOL   ForceClaim,
  [out, optional] PBOOL  Forced
);

Parameters

[in] HComDB

Handle to the COM port database that is returned by ComDBOpen.

[in] ComNumber

Specifies which COM port number the caller attempts to claim. A port number is an integer that can range from 1 to COMDB_MAX_PORTS_ARBITRATED.

[in] ForceClaim

Reserved for internal use only.

[out, optional] Forced

Reserved for internal use only.

Return value

ComDBClaimPort returns one of the following status values.

Return code Description
ERROR_SUCCESS
 The COM port number was not in use and is now logged as "in use".
ERROR_CANTWRITE
 The routine could not write to the database.
ERROR_INVALID_PARAMETER
 One of the following is true: The specified handle to the COM port database is not valid. The specified port number is greater than COMDB_MAX_PORTS_ARBITRATED.
ERROR_NOT_CONNECTED
 The routine could not access the database. To get extended error information, call GetLastError.
ERROR_SHARING_VIOLATION
 The specified port number is already in use.
ERROR_Xxx
 An internal error occurred; call GetLastError to get extended error information.

Remarks

Claiming a COM port number in the COM port database logs the port number as "in use". Note that the database does not contain information about the caller or device that claims a port number.

ComDBClaimPort runs in user mode.

For more information, see Obtaining and Releasing a COM Port Number.

Requirements

Requirement Value
Target Platform Desktop
Header msports.h (include Msports.h)
Library Msports.lib
DLL Msports.dll

See also

ComDBClaimNextFreePort

ComDBReleasePort

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