Setting linux directories writing rights to users

problem

In workdir, a directory I created

I want to:

• specific user named user1 to be able to create dirs and write his own files in /workdir/
• I keep writing and reading rights in /workdir/ and all future subdirs and files
• user1 is not able to modify my files and dirs in /workdir/

I can’t create a new group or deal with groups

how to solve

Add umask 002 in my .bashrc

cd /workdir
setfacl -d -m u:your_username:rwx .

setfacl -m u:user1:rwx .
setfacl -d -m u:user1:rwx .

chmod +t .