I have hundreds of Audacity project files, for which i need to do the same actions and effects.
how can i automate it. i came across that people says that is not possible with project files.
but, there isnt any way to do this complex job manually ?
That is probably not a good strategy.
Imho, projects should be thought of a “work in progress”, and the inherent problem of having hundreds of “works in progress” is that you can easily end up with hundreds of unfinished works and the unpleasant prospect of countless hours of work ahead. Also, because Audacity projects are often made up of hundreds or thousands of separate files, losing work is an accident waiting to happen.
Having said that, there may be ways to help you streamline the process somewhat.
Unless you are able to build Audacity from the source code (which can be difficult unless you have previous C/C++ programming experience) there will probably be no alternative than to open each project in turn (manually) to apply your effects. However, Chains can be used on the currently open projects, and can include exporting the finished file. So, depending on what “actions and effects” you want to perform, if those actions can be accomplished in a Chain, then you will only need to open each project once, apply the chain to the current project, close the project and move on to the next.
If you are familiar with building C/C++ applications from the source code, then there is a module available for Audacity called “mod-script-pipe” which allows Audacity to be controlled by scripting languages such as Perl, Python, etc. There is some information about this here: http://manual.audacityteam.org/o/man/scripting.html