search command in PATH instead of relying on execvpe()

[hanshuebner]

Motivation and Context

execvpe() is not available on macOS

Description

As execvpe() is not available on macOS, implement the PATH search in Rust so that things work on both platforms

How Has This Been Tested?

All tests pass

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Performance enhancement (non-breaking change which improves efficiency)
• Code cleanup (non-breaking change which makes code smaller or more readable)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (a change to man pages or other documentation)

Checklist:

• I have updated the documentation accordingly.
• I have added tests to cover my changes.

[hanshuebner]

You can probably see that I'm a Rust beginner, so maybe there is a better way to implement this. I would tend to think that the use of CStrs should really be confined to exec, but at least for the program_name, it seemed to be prudent to parse it into a Rust string so that it can be manipulated before finally turning it into a C string when invoking execve.

[FedericoPonzi]

Added few comments, thanks!

[hanshuebner]

I believe I have addressed your concerns. Thank you for your reviews!

[hanshuebner]

Looks much better with anyhow!, thank you!

[hanshuebner]

Hi @FedericoPonzi,

I'm somewhat confused with the test failure: It seems that the test that is failing is from a previous version but running against the branch version of Horust. This causes a mismatch in parameter count for store_service. Do you know what's happening here? Is anything else needed from my end to merge this?

Thank you!
Hans

[FedericoPonzi]

Sorry for the delay as I was AFK other the weekend till today. I'm taking a look at it right now, but I cannot understand what's going on either. It looks like to me that line 92 is fine:

Horust/tests/section_general.rs

Line 92 in 59f2b6b

store_service_script(temp_dir.path(), script_first, None, Some("a"));

I will merge it and deal with break on master separately. Thanks!

[hanshuebner]

Thank you!