TAR to CPIO Converter

TAR (Tape Archive) is a Unix archive format originating in Version 7 Unix) at AT&T Bell Labs in January 1979, originally designed for writing file backups to magnetic tape drives. Unlike ZIP or RAR, TAR is a pure archiving format that concatenates multiple files into a single stream without applying compression — each file is preceded by a 512-byte header block containing the filename, permissions, ownership, size, modification time, and checksum, followed by the file data padded to 512-byte boundaries. The format has evolved through several standards: the original V7 format, the POSIX.1-1988 ustar format (extending path lengths and adding support for more file types), and the POSIX.1-2001 pax format supporting extended attributes, arbitrary-length paths, and large file sizes. TAR is almost always paired with a compression tool — gzip (.tar.gz/.tgz), bzip2 (.tar.bz2/.tbz2), xz (.tar.xz), or others — producing a two-layer structure where compression operates on the entire stream for maximum efficiency. One advantage is exceptional Unix metadata fidelity — TAR preserves permissions, ownership, symbolic links, hard links, device files, and extended attributes with greater precision than most competing formats. Universal availability is another core strength: tar is a POSIX-mandated utility present on every Unix-like system, and tools on Windows and macOS handle TAR files natively. TAR remains the standard distribution format for source code, Linux filesystem images, container layers, and system backups.