I am using texstudio on mac os x. Each time I change some sentences in my .tex file and I need to see the results, I have to close the previous .pdf (if it is already opened) and regenerate the .pdf. Is it possible to update the pdf automatically without doing each time close open.thanks.
I'd recommend you to use the internal PDF viewer because it allows more accurate synchronization between PDF and source. Also, it does not have the closing issue. Check that you have the following settings
If you have a good reason to stay with Adobe Acrobat, here is a description how to setup DDE to automatically close the PDF before compilation: https://sourceforge.net/p/texstudio/feature-requests/650/