feature request: std::process::Command.envs()

[zackw]

You can add a vector of command-line arguments to a Command object with .args(), but there's no equivalent for environment variables. I'd like to be able to do things like

let filtered_env : Vec<(String, String)> = 
    std::env::vars().filter(|&(ref k, ref v)| /* criterion */).collect();

let status = Command::new("printenv")
    .stdin(Stdio::null())
    .stdout(Stdio::inherit())
    .env_clear()
    .envs(filtered_env)
    .status();

Right now I have to do instead

let mut cmd = Command::new("printenv");
cmd.stdin(Stdio::null());
cmd.stdout(Stdio::inherit());
cmd.env_clear();

for (ref k, ref v) in filtered_env {
    cmd.env(k, v);
}
let status = cmd.status();

which breaks the builder pattern and extends the scope of the Command object.

[brson]

This sounds reasonable to me considering args. If you want to submit a PR for the feature go ahead.

[alexcrichton]

@rfcbot fcp merge

[rfcbot]

Team member @alexcrichton has proposed to merge this. The next step is review by the rest of the tagged teams:

• @BurntSushi
• @Kimundi
• @alexcrichton
• @aturon
• @brson
• @dtolnay
• @sfackler

No concerns currently listed.

Once these reviewers reach consensus, this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for info about what commands tagged team members can give me.

[rfcbot]

🔔 This is now entering its final comment period, as per the review above. 🔔

[zackw]

I'm confused; hasn't this already been merged?

[Mark-Simulacrum]

Yes, but it's currently unstable. The FCP above starting means that the libs team believes the API is ready for stabilization.

[zackw]

Oh, ok. Thanks for the explanation.

[rfcbot]

The final comment period is now complete.