How to set permissions to default in Ubuntu?

Question

linux

I finished playing with the chmod command, set chmod -R 777 * for the home folder, and the same for all files in the /opt/ folder, now chrome and eclipse are not loaded, please tell me what to do? How to set permissions by default?

Answer 1

for home folder 775
for /opt 755

Answer 2

can man chmod ?? Is there an R key? But in this case it will be for all files and folders

Answer 3

There was also a jamb with Eclipse, I didn’t understand it - I just rearranged it.