Prepare runguard

Cargo.toml

@@ -1,3 +1,3 @@
 [workspace]
-members = ["judge-core", "judger"]
-resolver = "2"
+members = ["judge-core", "judger", "runguard"]
+resolver = "2"

runguard/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "runguard"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+clap = { version = "4.5", features = ["derive"] }

runguard/README.md

@@ -0,0 +1,5 @@
+# runguard
+
+A Rust version of
+[Domjudge runguard](https://github.com/DOMjudge/domjudge/blob/main/judge/runguard.cc)
+written in C++.

runguard/src/main.rs

@@ -0,0 +1,35 @@
+use clap::Parser;
+
+#[derive(Parser)]
+#[command(
+    override_usage = "runguard [OPTION]... <COMMAND>...",
+    about = "Run COMMAND with specified options.",
+    after_help = "Note that root privileges are needed for the `root' and `user' options. \
+If `user' is set, then `group' defaults to the same to prevent security issues, \
+since otherwise the process would retain group root permissions. \
+The COMMAND path is relative to the changed ROOT directory if specified. \
+TIME may be specified as a float; two floats separated by `:' are treated as soft and hard limits. \
+The runtime written to file is that of the last of wall/cpu time options set, \
+and defaults to CPU time when neither is set. \
+When run setuid without the `user' option, the user ID is set to the real user ID."
+)]
+struct Cli {
+    /// run COMMAND with root directory set to ROOT
+    #[arg(short, long)]
+    root: String,
+
+    /// run COMMAND as user with username or ID USER
+    #[arg(short, long)]
+    user: String,
+
+    /// run COMMAND under group with name or ID GROUP
+    #[arg(short, long)]
+    group: String,
+
+    #[arg(required = true)]
+    command: Vec<String>,
+}
+
+fn main() {
+    let _ = Cli::parse();
+}