/tmp 的permission是rwxrwxrwt
chmod 0777 /abc rwxrwxrwx
chmod 777 /abc rwxrwxrwx
chmod 1777 /abc rwxrwxrwt
The "t" character in your permission indicates that only the user (and the root) that has created the file inside of /tmp folder can delete/modify that specific file.
suppose chmod 1777 /tmp
here is 2 part
1 and 777
1 mean : this file only be deleted by root, its called sticky bit ( i guess) need to check again
rwx rwx rw t
owner group other only deleted by root
so this file is user has full access
group has full access
other has read and write
but this file only be deleted by root