Various additions and improvements

src/builtin/pwd.rs

@@ -0,0 +1,30 @@
+use crate::{jobs::{ChildProc, JobBldr}, libsh::error::ShResult, parse::{NdRule, Node}, prelude::*, procio::{borrow_fd, IoStack}};
+
+pub fn pwd(node: Node, io_stack: &mut IoStack, job: &mut JobBldr) -> ShResult<()> {
+	let NdRule::Command { assignments, argv } = node.class else {
+		unreachable!()
+	};
+
+	let child_pgid = if let Some(pgid) = job.pgid() {
+		pgid
+	} else {
+		job.set_pgid(Pid::this());
+		Pid::this()
+	};
+	let child = ChildProc::new(Pid::this(), Some("pwd"), Some(child_pgid))?;
+	job.push_child(child);
+
+	io_stack.append_to_frame(node.redirs);
+	let mut io_frame = io_stack.pop_frame();
+
+	io_frame.redirect()?;
+
+	let stdout = borrow_fd(STDOUT_FILENO);
+
+	let mut curr_dir = env::current_dir().unwrap().to_str().unwrap().to_string();
+	curr_dir.push('\n');
+	write(stdout, curr_dir.as_bytes())?;
+	io_frame.restore().unwrap();
+
+	Ok(())
+}