Re: How to overwrite a symbolic link?

[Bob Proulx]

Peng Yu wrote:
> Is there a way to overload operators like '>' and '>>' in bash, just
> as overloading in C++, etc. Suppose I have already made some bash
> program using '>' and '>>' without thinking about symbolic link, but I
> begin aware of them later. I would be cumbersome to add a test
> statement and deciding whether 'rm' or not for each usage of '>' and
> '>>'.

It sounds to me like you are trying to implement a "script space"
version of copy-on-write semantics?  Perhaps you should investigate
using one of the filesystem based solutions.  It would probably give
you a better result.

> A more general question is how to change the behavior of a program
> (for example compiled from C code) to delete symbolic link and write a
> new file, without recompiling the program.

A Comment: Symbolic links are designed to be transparent.  Normal
programs are not aware of them.

You could probably create an LD_PRELOAD library to intercept file
modification calls and then handle them in your own code.  But I think
it would be difficult to do it all completely correctly and not to
introduce bugs.  I advise against it.

Bob