I am new to Pd and to computing in general. Clumsy-english, naive questions. I don't mean to bother, please tell. I run Pd on windows 7 and about to run it on Linux

My question is when i click a bang in Pd, what actually happens under-the-hood so to speak? Is that a script-like message that is sent from Pd to the operating system ? Does Pd talk to the hardware directly ? What language do Pd and my computer share together ? Can I build patches by typing text somewhere instead of creating objects in the GUI window ? Can i monitor the scripted version of a patch building itself as I add objects in the GUI? Is "building" the proper english word?

Also can I run a patch by typing commands rather than clicking on things ? When running my patch, can i monitor the actual messages sent by Pd to the hardware or OS, and display them in a command-like window?

Not that I dislike the GUI at all, I actually like it exactly like it is, and coding is way out of my league, it's more that I am interested in learning how all of this works and also because I would like to feature this particular visual effect in a video piece I am currently working on.

Some actual english-speaking benefactor may fairly help by telling me the words he or she would use if was to search for ressources in english on this matter ?

Thank you.
Sebastien.

@Sebastien Hello Sebastien.

Yes, Pd does talk directly to the OS, and uses Tcl/Tk (the "Wish" application) for its GUI.
For what happens under the hood start reading here....
http://puredata.info/docs/manuals/pd/x2.htm
Look around on that site for answers, and then come back here with any questions.

Many very clever people have written (in C) externals that can do more than the basic installation, and in some cases can communicate with other programs and the OS.

Pd and Wish communicate through a port, so you might be able to sniff the traffic.
But I think they both make direct function calls to the OS, like any other program.

You can call Tk functions directly, and you can use [message( boxes to interact with those functions. In extended there was a small window at the bottom of the Pd terminal for sending directly to Tcl, and also an object...... [sys_gui] for sending from within a patch.
In 046.7 vanilla the prompt was hidden behind the help menu..... and now it seems to be gone.
I am sure it can be recovered from the old Tcl code.

But to script a command yourself you would have to make a "plugin" to be run and built into Pd at startup.
You will find everything on the Site I have linked to above.
........
http://puredata.info/docs/manuals/pd/x4.htm for C C++ and Fortran.
http://puredata.info/docs/guiplugins/GUIPlugins/ for plugins.
https://puredata.info/community/pdwiki/PdInternalMessages
etc.
David.

@Sebastien Pd is written in C which is then compiled to machine code, so it can directly communicate with the OS and the processor. Pd is open source and with your installation should come the directory "src" which contains the files with the C code. In another directory "tcl" you find the files with code in the language TCL which is used to create the actual GUI.

You can open patch files with a text editor and see that they are pretty simple. You can modify them but this is not advised as Pd will not open them if they don't conform with the correct syntax. Patch files are only updated by Pd if you save them.

Unfortunately no, there isn't something like a Pd REPL similar to what you get on a command line with Linux.