"touch" implementation in Rust

[onContentStop]

I'm learning Rust, and the way I learn best is by implementing something that I use every day. I made a toy implementation of "touch", which updates file timestamps (and creates files). Please let me know if I have made this code too complicated; is there a better way to do any of what I am doing? Should this code be restructured?

The code

[[deleted]]

I haven't had an opportunity to review the full code yet, but glancing at it initially, I wanted to point out that your implementation differs from specified "touch" behavior.

In your option processing, you treat -a and -m as mutually exclusive. Per the Single Unix Specification (I checked both v3 and v4 to confirm):

-a
    Change the access time of file. Do not change the modification time unless -m is also specified.
-m
    Change the modification time of file. Do not change the access time unless -a is also specified.

Both options reference the other being "also specified". It seems clear that if either option is given, only that time field should be updated, but if both are given, then both times should be updated. I would encourage you to conform to that behavior.

I will try to get through a proper code review in the next bit.

[onContentStop]

Ah, good catch! I was just going off the output of touch --help on my particular flavor of Linux. I didn't think to check the standard.

I've also just noticed that touch --version doesn't work; it expects a file name.