[File] New contributor's questions

Christos Zoulas christos at zoulas.com
Tue Apr 18 16:42:04 UTC 2023

On 2023-04-18 11:04 am, Vadim (vadcx) wrote:
> Hello, I want to contribute about a dozen of smaller formats and
> wanted to clarify a few things:
> 1. Preferred patch submission: via mailing list or the bug tracker?

I accept both, prefer the bug-tracker so that we can follow up 
if there are any issues.

> 2. Does the !:ext keyword have a meaning? I found it in Magdir/games
> but it's not in the man file.

Yes, it is a slash-separated list of extensions. I documented it now.

> 3. File formats that do NOT have a magic but are otherwise identified
> by a known file name + extension: are they out of scope of this
> project? The closest thing I see is the "language" check in "man file"

File(1) typically works on file data, not file names. The :ext notations
we've started collecting can be used in the future to provide such 
but we have not decided how to implement this (or if should be 
implemented at all).

> 4. I see there's a big definition file "Magdir/games", I plan to add
> about 10-15 definitions for single game. Should they go into the games
> too or is it okay to give it a separate definition file?

You can give it a separate file.

> 4.1 How does magic determine where one definition ends and the next
> one starts? (also not in man)

It can use absolute or relative offsets. There is a lot of documentation
and examples in the "magic" man page.

> 5. The string type can have a fixed length with "string/4" - limited
> to 4 bytes. Is it relevant to performance vs unbounded string?

It is not a length, it is a match indicator; again seem magic.4 or 
depending on your OS.

> I will take "i dont know" as an answer too (as a hint to dig into the
> source code myself). I'll update the manual with the answers received.

Please let me know if something is not clear or you have more questions!

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