Windows 2000 Junction Points

// Copyright 2000 Mikael Nordell (tamlin@algonet.se)
// Distributed without warranties. Use as you see fit, except for
// commercial purposes.
#include "../FSLinks/FSLinks.h"
#include <cstdio>
#include <cstdlib>	// definition of _MAX_PATH
#include <winioctl.h>
#include <tchar.h>


using namespace FSLinks;


void usage()
{
	const char szUsage[] =
		"MakeLink - Copyright 2000 Mikael Nordell\n"
		"\n"
		"Displays and/or modifies NTFS5 Junction Points\n"
		"\n"
		"MakeLink [junction where_to] [/L junction] [/D junction]\n"
		"\n"
		"  /D  Deletes Junction Point from specified junction directory.\n"
		"  /L  Lists where junction points to\n"
		"\n"
		"Examples:\n"
		"  MakeLink D:\\foo \"C:\\Program Files\"\n"
		"  MakeLink /L D:\\foo\n"
		"  MakeLink /D D:\\foo\n"
		"\n"
		"To mount a complete volume, use MOUNTVOL or Disk Administrator.\n";
	puts(szUsage);
}

void PrintJunctionInfo(LPCTSTR szSrc)
{
	const int cchDest = 512;
	TCHAR szDest[cchDest];
	
	const DWORD dwRet = GetJunctionPointInfo(szSrc, szDest, cchDest);
	if (dwRet == 0 || dwRet > cchDest) {
		printf("  Failed to get junction info for dir ");
		_tprintf(TEXT("\"%s\"\n"), szSrc);
		return;
	}

	printf("Junction points to ");
	_tprintf(TEXT("\"%s\"\n"), szDest);
}


extern "C" { void _setenvp() {} }

int _tmain(int argc, TCHAR *argv[])
{
	if (argc != 3) {
		usage();
		return 0;
	}

	if ((argv[1][0] == '/' || argv[1][0] == '-')) {
		switch (argv[1][1]) {
			case 'D':
			case 'd':
				PrintJunctionInfo(argv[2]);
				puts("");
				if (DeleteJunctionPoint(argv[2])) {
					puts("Deleted the above junction point.");
				} else {
					printf("Couldn't delete junction point ");
					_tprintf(TEXT("\"%s\"\n"), argv[2]);
				}
				break;

			case 'L':
			case 'l':
				PrintJunctionInfo(argv[2]);
				break;

			default:
				printf("Unknown option ");
				_tprintf(TEXT("%s\n"), argv[1]);
				usage();
		}
		return 0;
	}

	LPCTSTR szSrc = argv[1];

	TCHAR szVol[4] = TEXT("x:\\");
	if (szSrc[1] == ':') {
		szVol[0] = szSrc[0];
	} else {
        TCHAR curdirstr[_MAX_PATH];
        if (GetCurrentDirectory(sizeof(curdirstr), curdirstr)) {
			if (curdirstr[1] == ':') {
				szVol[0] = curdirstr[0];
			}
		}
	}

	DWORD dwCompLen;
	DWORD dwFsFlags;
	if (!GetVolumeInformation(szVol, 0, 0, 0, &dwCompLen, &dwFsFlags, 0, 0)) {
		const DWORD dwErr = GetLastError();
		printf("  GetVolumeInformation for ");
		_tprintf(TEXT("\"%s\""), szVol);
		printf(" failed (%d)!\n", dwErr);
		return -1;
	}

	szVol[2] = 0;

	if (!(dwFsFlags & FILE_SUPPORTS_REPARSE_POINTS)) {
		printf("  The filesystem on ");
		_tprintf(TEXT("\"%s\""), szVol);
		puts(" does not support Reparse Points");
		return -1;
	}

	const DWORD dwFA = GetFileAttributes(szSrc);
	if (dwFA == 0xffffffff) {
		printf("  Can't get info for ");
		_tprintf(TEXT("\"%s\""), szSrc);
		puts("\n  Does the directory really exist?");
		return -1;
	}

	int nRet = 0;
	if (!CreateJunctionPoint(argv[1], argv[2])) {
		printf("Couldn't create link ");
		nRet = -1;
	} else {
		printf("Created link ");
	}
	_tprintf(TEXT("\"%s\" -> \"%s\"\n"), argv[1], argv[2]);

	return nRet;
}