Initial commit for fern

src/builtin/echo.rs

@@ -0,0 +1,53 @@
+use shellenv::jobs::{ChildProc, JobBldr};
+
+use crate::{libsh::utils::ArgVec, parse::parse::{Node, NdRule}, prelude::*};
+
+pub fn echo(node: Node, shenv: &mut ShEnv) -> ShResult<()> {
+	let rule = node.into_rule();
+
+	if let NdRule::Command { argv, redirs } = rule {
+		let argv = argv.drop_first().as_strings(shenv);
+		let mut formatted = argv.join(" ");
+		formatted.push('\n');
+
+		if shenv.ctx().flags().contains(ExecFlags::NO_FORK) {
+			shenv.collect_redirs(redirs);
+			if let Err(e) = shenv.ctx_mut().activate_rdrs() {
+				eprintln!("{:?}",e);
+				exit(1);
+			}
+			if let Err(e) = write_out(formatted) {
+				eprintln!("{:?}",e);
+				exit(1);
+			}
+			exit(0);
+		} else {
+			match unsafe { fork()? } {
+				Child => {
+					shenv.collect_redirs(redirs);
+					if let Err(e) = shenv.ctx_mut().activate_rdrs() {
+						eprintln!("{:?}",e);
+						exit(1);
+					}
+					if let Err(e) = write_out(formatted) {
+						eprintln!("{:?}",e);
+						exit(1);
+					}
+					exit(0);
+				}
+				Parent { child } => {
+					shenv.reset_io()?;
+					let children = vec![
+						ChildProc::new(child, Some("echo"), Some(child))?
+					];
+					let job = JobBldr::new()
+						.with_children(children)
+						.with_pgid(child)
+						.build();
+					wait_fg(job, shenv)?;
+				}
+			}
+		}
+	} else { unreachable!() }
+	Ok(())
+}