Util: check parent process for filename

[th1000s]

Usecase: With delta used as a pager the command git blame main.rs calls
delta, but the piped data does not mention the filename. Instead try to
get the filename extension from the parent git process.

[th1000s]

Nice, this even works on windows, thanks to sysinfo:

windows-latest, x86_64-pc-windows-msvc:
    test utils::tests::test_process_parent_cmd_args ... ok

[dandavison]

Excellent! (There seem to be some test failures on one of the linux builds)

[dandavison]

I wonder if there is a crate dedicated to parsing arbitrary command lines known only at run time?

[th1000s]

Since this is more a command line ignorer than parser it is a rather simple function, see skip_uninteresting_args.

[th1000s]

Updated to also work in other cases, such as piped input (git blame src/main.rs | delta), but this is not guaranteed to work if the git process is too fast or the data too small.

The tests failed on ARM because there they are not executed on hardware but in emulation, so I try to detect that.

Also, utils.rs..., any other ideas? :)

[dandavison]

Also, utils.rs..., any other ideas? :)

How about process_utils.rs? (We already have bat_utils/ and syntect_utils/; it might be nice to reorganize as utils/* at some point.) EDIT I'm doing that in #775

I'm using the API provided in this PR in #774 to interrogate git grep arguments; very useful!

[dandavison]

Merged -- it looks like the only test complaints were clippy complaining that things were not called, as indeed they will not be until we use this in #761, and the coverage test for which I'll try adding tarpaulin as an expected argument along with test.

Thanks very much for this -- it is already quite sophisticated.