How to read text from annother application

[wjackson153]

For windows there was a utility that you could hover your mouse over a 3rd party application windows contents
and it would extract the text into a text control.

My question is how could this be achieved on linux,  I can not find a 3rd party  app that can perform this task
on a linux machine.  Windows apps use an api GetWindowText,   does linux have a simular concept


This is my goal,   open for example Gcalculator   , put mouse over the input field where I have input for example
500,  my app should extract the value from the input field.


Is this feasable?

[wjackson153]

Is anyone familar with ptrace and wine,  peek, poke etc

if so could you post a breif example how I can peek at the a input fields contents
and relay the contents as a string that can  be imported to text file or stdout, etc..