bool IsSparseFile(HANDLE h) DWORD bytes; FILE_ATTRIBUTE_TAG_INFO tag = 0; DeviceIoControl(h, FSCTL_GET_NTFS_FILE_RECORD, ...); return (tag.FileAttributes & FILE_ATTRIBUTE_SPARSE_FILE) != 0;

// Write file content if (!info.isDirectory) HANDLE h = CreateFileW(path.c_str(), GENERIC_READ, ...); WriteFileContent(h, info.size);

On extraction, recreate ADS via CreateFile with filename:streamname . POSIX mode → NTFS conversion:

Abstract The tar (tape archive) utility is a cornerstone of file archiving in Unix-like systems, but native Windows environments lack a built-in equivalent. This paper presents the design and implementation of a Windows-native tar utility that emulates POSIX behavior while adhering to Windows file system semantics, path conventions, and security models. Key contributions include handling of alternate data streams, long path names, permission mapping between POSIX and NTFS ACLs, and integration with PowerShell and CMD. Performance benchmarks and compatibility tests against GNU tar 1.34 are provided. 1. Introduction The tar format (POSIX.1-2001) remains the dominant archiving standard for software distribution, system backups, and container images (e.g., Docker). However, Windows users traditionally rely on third-party ports (e.g., GNUWin32, Cygwin) or proprietary tools (WinRAR, 7-Zip). These solutions introduce dependencies or incomplete POSIX emulation.

class FilterStream virtual size_t read(BYTE* buf, size_t len) = 0; virtual size_t write(BYTE* buf, size_t len) = 0; ; class GzipFilter : public FilterStream z_stream zs; // inflate/deflate with Z_SYNC_FLUSH ;

Supported via dynamically loaded DLLs (zlib1.dll, libbz2.dll, liblzma.dll) or static linking. 5.1 Alternate Data Streams (ADS) Extended tar format using filename:streamname syntax:

:: List contents of a .tar.xz file tar -tf software.tar.xz

// Windows-specific mode mapping header.mode[0] = '0'; header.mode[1] = info.isReadOnly ? '4' : '6'; strcpy(header.magic, "ustar");