Once a project is completed it is convenient to have some way to package the components so that they can be easily conveyed to others. The UNIX convention for this is tar + gzip. A hierarchy of directories including the current one is easily collected into a single file with the command
tar cvf - . >/tmp/project.tarwhich produces a file project.tar in the /tmp directory. The only delicate aspect of this is to avoid putting the target tar file into the hierarchy being tarred since this creates an infinite loop. Compression can then be done using either compress or gzip, the latter seems preferable since it is somewhat more efficient than the older compress. Tar files may include data, SPLUS functions, FORTRAN source, postscript files, even binary load modules. Unpackaging project archives is also straightforward. The Unix commands uncompress and gunzip may be used together with tar.
Of course, often, one has only a handful of files that one would like to package up for email transmission. This is most conveniently done with a shell archive, see the man page for the command shar for details. Most of the submissions to statlib are available in this format at the website http://www.statlib.cmu.edu. You might also explore the packaging of software, data, and text at the our local site http://www.econ.uiuc.edu.