Initial commit for fern

src/shellenv/mod.rs

@@ -0,0 +1,111 @@
+use std::env;
+
+use jobs::Job;
+
+use crate::prelude::*;
+
+pub mod jobs;
+pub mod logic;
+pub mod exec_ctx;
+pub mod meta;
+pub mod shenv;
+pub mod vars;
+
+/// Calls attach_tty() on the shell's process group to retake control of the terminal
+pub fn take_term() -> ShResult<()> {
+	attach_tty(getpgrp())?;
+	Ok(())
+}
+
+pub fn disable_reaping() -> ShResult<()> {
+	log!(TRACE, "Disabling reaping");
+	unsafe { signal(Signal::SIGCHLD, SigHandler::Handler(crate::signal::ignore_sigchld)) }?;
+	Ok(())
+}
+
+/// Waits on the current foreground job and updates the shell's last status code
+pub fn wait_fg(job: Job, shenv: &mut ShEnv) -> ShResult<()> {
+	log!(TRACE, "Waiting on foreground job");
+	let mut code = 0;
+	attach_tty(job.pgid())?;
+	disable_reaping()?;
+	let statuses = write_jobs(|j| j.new_fg(job))?;
+	for status in statuses {
+		match status {
+			WtStat::Exited(_, exit_code) => {
+				code = exit_code;
+			}
+			WtStat::Stopped(pid, sig) => {
+				write_jobs(|j| j.fg_to_bg(status))?;
+				code = sys::SIG_EXIT_OFFSET + sig as i32;
+			},
+			WtStat::Signaled(pid, sig, _) => {
+				if sig == Signal::SIGTSTP {
+					write_jobs(|j| j.fg_to_bg(status))?;
+				}
+				code = sys::SIG_EXIT_OFFSET + sig as i32;
+			},
+			_ => { /* Do nothing */ }
+		}
+	}
+	take_term()?;
+	shenv.set_code(code);
+	log!(TRACE, "exit code: {}", code);
+	enable_reaping()?;
+	Ok(())
+}
+
+pub fn log_level() -> crate::libsh::utils::LogLevel {
+	let level = env::var("FERN_LOG_LEVEL").unwrap_or_default();
+	match level.to_lowercase().as_str() {
+		"error" => ERROR,
+		"warn" =>  WARN,
+		"info" =>  INFO,
+		"debug" => DEBUG,
+		"trace" => TRACE,
+		_ =>       NULL
+	}
+}
+
+pub fn enable_reaping() -> ShResult<()> {
+	log!(TRACE, "Enabling reaping");
+	unsafe { signal(Signal::SIGCHLD, SigHandler::Handler(crate::signal::handle_sigchld)) }.unwrap();
+	Ok(())
+}
+
+pub fn attach_tty(pgid: Pid) -> ShResult<()> {
+	if !isatty(0).unwrap_or(false) || pgid == term_ctlr() {
+		return Ok(())
+	}
+	log!(DEBUG, "Attaching tty to pgid: {}",pgid);
+
+	if pgid == getpgrp() && term_ctlr() != getpgrp() {
+		kill(term_ctlr(), Signal::SIGTTOU).ok();
+	}
+
+	let mut new_mask = SigSet::empty();
+	let mut mask_bkup = SigSet::empty();
+
+	new_mask.add(Signal::SIGTSTP);
+	new_mask.add(Signal::SIGTTIN);
+	new_mask.add(Signal::SIGTTOU);
+
+	pthread_sigmask(SigmaskHow::SIG_BLOCK, Some(&mut new_mask), Some(&mut mask_bkup))?;
+
+	let result = unsafe { tcsetpgrp(borrow_fd(0), pgid) };
+
+	pthread_sigmask(SigmaskHow::SIG_SETMASK, Some(&mut mask_bkup), Some(&mut new_mask))?;
+
+	match result {
+		Ok(_) => return Ok(()),
+		Err(e) => {
+			log!(ERROR, "error while switching term control: {}",e);
+			unsafe { tcsetpgrp(borrow_fd(0), getpgrp())? };
+			Ok(())
+		}
+	}
+}
+
+pub fn term_ctlr() -> Pid {
+	unsafe { tcgetpgrp(borrow_fd(0)).unwrap_or(getpgrp()) }
+}