How can i specify which group can read and write files in directory

Question

i have two groups

• boys
• girls

boys have users

• pete
• ali

girls have users

• alice
• mary

i have d1 directoy in home/pete

I want to let only pete can read and write the files in that folder,

And ali can read only

And for group grils can't read or write

i used

chmod g+u=rxw d1

And now, pete only can modify the files, and ali can read only, so the first part done

But grils group users can do what ali can, so they can read the files

How can i exclude girls group ?

Answer 1

chown pete:boys home/pete

chmod 0750 home/pete

pete would get full control

ali would get enter & read permissions through the group 'boys'

girls wouldn't even get into the directory