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What are the permissions for reading a file?
Your permissions are set now to read just for “group” and “others”. As said in the comments, the user rick does belong to the group, but what counts is the fact that is the owner, so the permissions checked are the ones on the first column, which happen to be —, that is 0.
Why does Linux not allow reading a file?
Since the accessing process has userid “rick”, only the owning-user permissions, which forbid reading, are checked. Only if the accessing process does not have the same userid as the owner of the file will the kernel consider the possibility that it might be a member of the file’s group.
Can a process deny access to a file?
Any process running as the owning user of a file can use the chmod system call to set its permission bits to whatever they want, so denying read or write access to the owning user is ineffective as a security measure, but it can still be a useful safety measure.
Do you need permission to access files in a directory?
Read permission is needed to access the names of files in a directory. Execute (a.k.a. search) permission is needed to access the inodes of files in a directory, if you already know the file’s name.
How to remove write permission from a group?
Will remove write permission from group and other, but not touch execute permission. You can also use find just to set the directories or just to set files: This will only touch directories, setting read and execute permission on all directories and setting write permission for the owner.
When to use relative permissions instead of absolute permissions?
When you change a directory permission to 644, you are unable to read the files in that directory although you can read that directory to see it exists. $ chmod -R 0755 . Otherwise, you can see the directory, but not access the information in that directory. You maybe better off using relative permissions instead of absolute permissions: