CDnsClient::GetDefaultHostFile
INT GetDefaultHostFile(
LPTSTR lpszFileName,  
INT cchMaxLength  
);

The GetDefaultHostFile method returns the fully qualified path name of the host file on the local system. The host file is used as a database that maps an IP address to one or more hostnames, and is used by the GetHostAddress and GetHostName method. The file is a plain text file, with each line in the file specifying a record, and each field separated by spaces or tabs. The format of the file must be as follows:

ipaddress hostname [hostalias ...]

For example, one typical entry maps the name "localhost" to the local loopback IP address. This would be entered as:

127.0.0.1 localhost

The hash character (#) may be used to specify a comment in the file, and all characters after it are ignored up to the end of the line. Blank lines are ignored, as are any lines which do not follow the required format.

The default hosts file is stored in C:\Windows\system32\drivers\etc\hosts and may or may not exist on a given system. Note that there is no extension for this file.

Parameters

lpszFileName
Pointer to a null-terminated string buffer that will contain the fully qualified file name to the default host file. It is recommended that this buffer be at least MAX_PATH characters in size. This parameter may be NULL, in which case the method will return the length of the string, not including the terminating null byte.
cchMaxLength
The maximum number of characters that may be copied to the string buffer.

Return Value

If the method succeeds, the return value is length of the string. A return value of zero indicates that the default host file could not be determined for the current platform. To get extended error information, call GetLastError.

Remarks

This method only returns the default location of the host file and does not determine if the file actually exists. It is not required that a host file be present on the system.

The default host file is processed before performing a nameserver lookup when resolving a hostname into an IP address, or an IP address into a hostname.

To specify an alternate local host file, use the SetHostFile method.

Requirements

Client: Requires Windows Vista, Windows XP or Windows 2000 Professional.
Server: Requires Windows Server 2008, Windows Server 2003 or Windows 2000 Server.
Header: Include cstools6.h.
Library: Use csdnsav6.lib.
Unicode: Implemented as Unicode and ANSI versions.

See Also

GetHostAddress, GetHostFile, GetHostName, SetHostFile


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