[tools] Add chmod in tools.files

[uilianries]

Changelog: Feature: Integrate chmod feature in tools.files.
Docs: conan-io/docs#4038

The tools.files.chmod is a wrapper for os.chmod, simplifying it's usage.

It will change permissions only related to the file's owner and will follow os.chmod behavior as well. On Windows, chmod is limited to writing permission changes; adding executable permission is out of scope.

Reference: https://docs.python.org/3/library/os.html#os.chmod

closes #8003

/cc @memsharded

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[valgur]

Suggested change

	def chmod(conanfile, path:str, read:bool, write:bool, execute:bool, recursive:bool=False):
	def chmod(conanfile, path:str, read:bool=None, write:bool=None, execute:bool=None, recursive:bool=False):

Using None to mean "unchanged" for a chmod +x or chmod +w equivalent would provide a very useful and intuitive interface, e.g. chmod(self, some_exe, execute=True)?

[memsharded]

Why? ConanCenter recipes very rarely do this, only in a couple of occcasions.
And chmod in Windows still can change the read-only flag, so if the function has read argument, then it should work.

[uilianries]

Okay, but what should be done when passing execute or write? Just ignore or rise an error?

[memsharded]

Whatever the underlying os.chmod does. This is mostly a convenience wrapper for it, the overall expected behavior should be aligned.

[memsharded]

I am not sure the default should be setting the permissions for everyone, but just for the current user.
Recipes in ConanCenter set S_IXUSR/S_IXEXEC only, not all.

[memsharded]

I know some recipes also do os.chmod(filename, os.stat(filename).st_mode | 0o111), but maybe this has to be checked with @jcar87 too

[uilianries]

Agreed. Mostly of the cases are related to tool-requires only.

[memsharded]

Ok, looking better now, still I wonder why the read permission will be different to the others, is it not enough that it has "user" read permissions (if for some reason it didn't have it)?

[uilianries]

Done, only changed owner permission.

[memsharded]

Looking good to me.
Assigning it to @jcar87 for review and check regarding ConanCenter usage

[memsharded]

Ok, looking better now, still I wonder why the read permission will be different to the others, is it not enough that it has "user" read permissions (if for some reason it didn't have it)?

[uilianries]

Ok, looking better now, still I wonder why the read permission will be different to the others, is it not enough that it has "user" read permissions (if for some reason it didn't have it)?

Only leftover, gonna change it too.