In the linux/unix machine I am using, I am just a normal user. However, I want a version control system to manage my files to prevent accidental delete/rename/lost/modification. Obviously I don't have the right to install a version control into the machine. Do we have a portable version of such version control system?
Most likely I use AIX. or Red Hat Linux.
Version control system is a program like any other. You can install it system-wide or locally if you like. Read the first two lines of GIT installation instructions for example.
Also, if you are going to build anything to run as normal user, you might be interested in the question about running your own programs.
For your intended use, the ancient, but serviceable RCS or CVS systems may already exist on both AIX and Red Hat, and are perfectly acceptable for a single user. They're easy to learn, fast, aren't heavy on resources, and are very, very well debugged code. IDE and GUI clients abound for CVS. You can compile both systems yourself, and put the executables just about anywhere (like $HOME/bin).
CVS allows you to put a "repository" in an arbitrary directory, which might get you backups (of the repository) for free, eliminating that headeache.
With RCS, you've either got ugly RCS/ directories everywhere, or you can use symlinks to a "repository".
Sometimes old school is the best school.
I really like the simplicity and all-in-one "self-contained" features of Fossil, especially for smaller "projects" like version control of configuration files and scripts. I haven't used it for larger projects but there are a number of testimonials on the site:
http://fossil-scm.org/index.html/doc/trunk/www/reviews.wiki
and an "open source" book available for download at the web site that gives a solid introduction to how to use fossil. Fossil is BSD licensed, and simple to use (i.e it replaces ci co rcs) . but it has lots of advanced DVCS features as well, just like mercurial and git.
Bonus: it's fairly easy to get running on different platforms: *BSD, Windows, Unix, Linux and OS X, and a small static binary has built in networked VCS, wiki and bug tracker(!!) It's worth trying (and following the development) even if other tools are more popular at the moment.
