xtask: add cargo backed runner

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

.cargo/config

@@ -0,0 +1,2 @@
+[alias]
+xtask = "run --package xtask --"

.gitignore

@@ -1,2 +1,16 @@
 result
 result-*
+
+# Created by https://www.toptal.com/developers/gitignore/api/rust
+# Edit at https://www.toptal.com/developers/gitignore?templates=rust
+
+### Rust ###
+# Generated by Cargo
+# will have compiled files and executables
+/target/
+
+# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
+# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
+Cargo.lock
+
+# End of https://www.toptal.com/developers/gitignore/api/rust

Cargo.toml

@@ -0,0 +1,4 @@
+[workspace]
+members = [
+  "xtask",
+]

xtask/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "xtask"
+version = "0.1.0"
+authors = ["Harsh Shandilya <me@msfjarvis.dev>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+walkdir = "2.3.2"
+xshell = "0.1.9"

xtask/src/main.rs

@@ -0,0 +1,37 @@
+use std::error::Error;
+use std::process::Command;
+use walkdir::WalkDir;
+
+fn main() -> Result<(), Box<dyn Error + 'static>> {
+    let args = std::env::args();
+    if args.len() == 0 {
+        println!("Provide a command");
+        return Ok(());
+    }
+    match std::env::args().nth(1) {
+        None => {}
+        Some(arg) => match arg.as_str() {
+            "clean" => {
+                for entry in WalkDir::new(".").into_iter().filter_map(|e| e.ok()) {
+                    if entry.path().to_str().unwrap().contains("./result") {
+                        std::fs::remove_file(entry.path().to_str().unwrap())?;
+                    }
+                }
+            }
+            "hash" => {
+                let repo = std::env::args().nth(2).unwrap();
+                let tag = std::env::args().nth(3).unwrap();
+                let url = format!(
+                    "https://github.com/{}/archive/{}.tar.gz",
+                    repo, tag
+                );
+                let output = Command::new("nix-prefetch-url")
+                    .args(&["--type", "sha256", "--unpack", url.as_str()])
+                    .output()?;
+                println!("{}", std::str::from_utf8(&output.stdout).unwrap());
+            }
+            _ => {}
+        },
+    };
+    return Ok(());
+}