Files on this server ending in a .tar extension are standard Unix TAR archives. The TAR archive format is an aggregation of a single or multiple files into a single archive, typically preserving the file dates, permissions and ownerships of each individual file or directory.

Unlike the ZIP format, TAR archives are not inherently compressed; instead, supporting tools like GNU zip may be used to compress a TAR archive to reduce its size. This type of compressed TAR archive is typically denoted by the combined extension .tar.gz.

One reason that this web site supports a combination of gzipped TAR archives and ZIP archives is that a tar utility is readily available on most, if not all, Unix systems. As such, it is sometimes an unconscious act to build a gzipped TAR archive instead of the more flexible ZIP archive. For engineering modeling, which has strong support in the Unix realm, it thus has made sense to provide resources in a format suitable for Unix systems. With recent changes in the computing world, notably wider engineering application support for Windows NT, we'll look to standardize on the ZIP format for new archives.

Downloadable Resources:

TAR compatible application resources are listed as follows:

> Tar: A local copy?

If your primary work environment is a Unix system, please look in the default path (Eg. "echo $PATH" or "echo $path") for a local tar utility. Additionally, typing

man tar

at the Unix shell prompt should provide useful information on how to use the tar utility.

> WinZip: A Commercial Solution

Nico Mark Computing, Inc. sells its WinZip product, a commercial ZIP solution, for the Windows 3.x and Win32 (Intel) platforms. The product is completely self-supporting for the ZIP and GZIP file formats, and requires no external support tools to work with files in these formats. Evaluation versions may also be available.

> University of Michigan: MacIntosh Archive

MacIntosh Compression/Archive Utilities
MacIntosh Unix Utilities

The University of Michigan (UMich) MacIntosh archive is a fairly comprehensive source of general purpose utilities, including utilities for working with TAR archives. Look for files starting with "tar", or for the "tar" keyword in the archive index00.txt files.

If there are problem connecting to UMich, consider searching another MacIntosh oriented archive site, or one of the UMich mirror sites.

> GNU Tar

MIT
Digital Equipment

GNU tar is slightly different from standard tar in that it supports integration with GNU zip, which makes it a very powerful tool for managing compressed archives through the addition of a single command line option. Some also consider GNU tar to be somewhat more flexible and reliable than the standard tar utility shipped with many Unix systems.

The licensing for GNU software prohibits distribution of binaries without distributing an accompanying set of the application sources. Look for files beginning with the string "tar". The source distribution has support for building binaries for a number of different Unix platforms; a C compiler and appropriate development tools are required.

> GNU Binaries and Source for Selected Systems

Please download a copy of the related GNU source when downloading a binary for your system. NHTSA doesn't currently maintain a local repository of TAR binaries, but many of the popular web and anonymous FTP archives should have versions for the more popular environments and operating systems.

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