CoCoA » CoCoA-5

Here is an excerpt from comment 13 of issue #990:

Here is a quick summary of what I think the installation "script" for CoCoALib does:

• create new dir with name like /usr/local/include/CoCoA-0.99700 and put the header files in there
• create a symbolic link so that /usr/local/include/CoCoA actually "points to" the directory created above
• put the library in /usr/local/lib/libcocoa-0.99700.a
• create a symbolic link so that /usr/local/lib/libcocoa.a "points to" the latest library

An advantage of this approach is that if installation goes wrong (but not horribly wrong, like when I wiped out half of /usr),
then a "skilled" use can simply move the symbolic links to point back to the previous installation. Note that the previous
installation is not removed.
I think doing something similar could be reasonable for CoCoA-5 too.

• all files for the distribution are put into cocoa-5.3.0
• then we make a symbolic link so that cocoa-5 (or even just cocoa???) points to the latest version
• any older installations are not removed (but perhaps an informative message about them could be printed?)

Does this imply that the user must run a script to "install" CoCoA-5: the script would make the appropriate symbolic links.

It may be difficult to do this on Microsoft?

John Abbott wrote:

I may be difficult to do this on Microsoft?

This is the point: I have no clue how to make a script in M$

We can do it anyway for Linux and MacOS. Hopefully someone will tell us how to do it for Microsoft.

• the root dir is /usr/local/bin/CoCoA-5/ or maybe just CoCoA instead of CoCoA-5???
• inside root dir each version unpacks into ROOTDIR/CoCoA-5.3.2/ say (what to do if this subdir already exists? error? flag to force?)
• make a symbolic link from ROOTDIR/CurrentVersion to the just unpacked dir
• this means that all files relevant to CoCoA-5 are in ROOTDIR/CurrentVersion/

If an experienced user wants to switch back to an earlier version then it suffices to change just the symlink.

A similar structure can also be built in a personal file-space (so there would be no need to be a sudoer).

Just to remember: we already have pretty good scripts for configuration on Mac and on Linux.

On MacOS a user can install software easily from a "dpkg" file.
It would be nice to have a single-file-install capability for Linux.

One possibility is a "shar" file. Not sure how well that fits with a large TARGZ file.
How standard is gzip?

UPDATE: Wikipedia suggests that "shar" files are too risky... but anyway a helpful installation script has to be executable... mmm?