hostname: add command implemenation

Author: nadzyah

Cargo.lock

@@ -9,3 +9,17 @@ authors = [
 license = "MIT"
 
 [dependencies]
+clap = { version = "4.5", features = ["derive"] }
+libc = "0.2"
+nix = { version = "0.30", features = ["hostname", "net"] }
+thiserror = "2.0"
+
+[[bin]]
+name = "hostname"
+path = "bin/hostname.rs"
+
+[lints.rust]
+unsafe_op_in_unsafe_fn = { level = "deny" }
+
+[lints.clippy]
+undocumented_unsafe_blocks = "warn"

Cargo.toml

@@ -0,0 +1,3 @@
+fn main() {
+    net_tools_rs::hostname_main();
+}

bin/hostname.rs

@@ -0,0 +1,31 @@
+use std::io;
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum NetToolsError {
+    #[error("IO error: {0}")]
+    Io(#[from] io::Error),
+
+    #[error("System error: {0}")]
+    Nix(#[from] nix::errno::Errno),
+
+    #[error("Invalid argument: {0}")]
+    InvalidArgument(String),
+
+    #[error("Permission denied: {0}")]
+    PermissionDenied(String),
+
+    #[error("Not found: {0}")]
+    NotFound(String),
+
+    #[error("Name too long: {0}")]
+    NameTooLong(String),
+
+    #[error("Protocol family not supported")]
+    ProtocolNotSupported,
+
+    #[error("{0}")]
+    Other(String),
+}
+
+pub type Result<T> = std::result::Result<T, NetToolsError>;