Explain in Russian what access rights 777 are?

Question

linux

I can't figure out what it is. If they allow everything, then why put them then? Some write that they need to be put on files with a config, is this on purpose so that you can find out the data later? You just thought I was an idiot, but I just don't understand... Do I need to put them on ajax handlers? After all, in fact, the user does not need to have access to them. I don’t understand ... Explain in simple Russian, which files to put them on and what do they do? They give an error Access forbidden! 403? Why, if I enter the /img directory in the browser, I see a list of pictures, but if I go to /pages, then I get Access forbidden! ? So many questions and so few answers...

Answer 1

First of all, put the tags of Apache and the CMS over which you are now giving birth to a hedgehog :)
File access rights are exactly file access rights, by the way, this is also in Windows, only there the muzzle immediately translates them into a readable form.
Put them on all files. They - all of a sudden - determine the file's permissions on the part of the owner , owner group, and others .
These three concepts are the fundamental concept of UNIX. Each file has an owner and an owner group. All those who do not belong to them - belong to others . Accordingly, each of these categories has the following rights:
- read a file (for a directory - read its contents)
- change a file (for a directory - rights to delete / rename)
- execute a file (for a directory - go to it)
And then each right is assigned bit:
1 - execute (denoted by x)
2 - change (denoted by w)
4 - reading (denoted by r)
(for a special group:
1 - sticky bit
2 - sgid
4 - suid)
and an 8-ary number is formed, usually consisting of 4 groups (although the first, where 0, is often omitted). Groups are in order - special, owner, group, others. Thus, the rights 0755 on the file will mean:
the owner has all rights
the group can read and execute
others can read and execute
this typical rights for the program
But the rights 0750 on the directory mean that only the owner or group of owners can go into it, all the rest will receive an EPERM error (and how it will be interpreted and what message will be issued is up to the programmer)
Start reading Apache literature to get rid of this mess in your head. There is no 403 error in UNIX and no concept of "access forbidden". There is an EPERM return code that will return the corresponding system call
Because you are confusing system access rights and Apache access rights - which is not the same thing at all ...

Answer 2

Why, when entering the site address, if I go to the /img directory, I see a list of pictures, and if I go to /pages, then I get Access forbidden! ?

It depends on whether indexing is enabled in the directory and the web server's access rules for these folders.

Answer 3

If you see a list of pictures, it's already bad.
In general, read about web servers. For example about Apache.