Re: How to overwrite a symbolic link?

[Marc Herbert]

Le 07/05/2010 16:02, Peng Yu a écrit :
> I can copy the whole
> directory and then modify one file in the newly copied N files. But
> I'll lose track of which file has been changed later on, which is
> important to me.

You will not lose track of the changed files: just run a recursive
diff comparing the old and new directories and you will see what
was/has changed (this is actually the poor man's version control
system).


> Suppose I have N files in a directory that does some job. Lets say M
> (<N) files are primary files and N-M files are derived from these M
> files (say, there are a number of programs, each takes some of the M
> files to generate some of the N-M files).
> [...]
> Instead, I'd rather create symbolic link for all the N-M-1 primary
> files but copy only one remaining file and modify it. Remember, I
> can't tell which are primary files and which are derived files. So I
> can not do so.
> 
> One solution is create symbolic link to N-1 files as long as I can
> overload '>' and '>>' and the open file function call.

So you are really trying to re-invent some copy-on-write/versioning
file system by hacking symbolic links and redirections. This looks
like a lot of pain. You'd better start by looking at existing
solutions; even if none is ideal for your case, you would at least
leverage the existing knowledge and experience in this field instead
of starting from zero.


> Let me know if you have any thought on solving this problem.
 
Since you are using the wrong tool for the job I am afraid you are
going to be rather alone on this road.

Cheers,

Marc