elementary shell behavior: can kick off a foreground process and

handle signals

src/bin/main.rs

@@ -14,21 +14,27 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-use nu_ansi_term::{Color, Style};
-use dirs::home_dir;
+
 use relish::ast::{eval, lex, Ctr, Seg, SymTable, run, load_defaults, load_environment};
 use relish::stdlib::{dynamic_stdlib, static_stdlib};
+use relish::aux::ShellState;
+
+use std::cell::RefCell;
+use std::rc::Rc;
+use std::borrow::Cow;
+use std::env;
+
+use nix::unistd;
+use nu_ansi_term::{Color, Style};
+use dirs::home_dir;
 use reedline::{
     FileBackedHistory, DefaultHinter, DefaultValidator, Reedline, Signal,
     Prompt, PromptEditMode, PromptHistorySearch, PromptHistorySearchStatus,
 };
-use std::borrow::Cow;
-
-
-use std::env;
 
 #[derive(Clone)]
 pub struct CustomPrompt(String, String, String);
+
 impl Prompt for CustomPrompt {
     fn render_prompt_left(&self) -> Cow<str> {
         {
@@ -75,12 +81,20 @@ fn main() {
     let hist_file_name = home_dir.clone() + HIST_FILE;
     let cfg_file_name = home_dir + CONFIG_FILE_DEFAULT;
 
+    let shell_state_bindings = Rc::new(RefCell::from(ShellState {
+        parent_pid: unistd::Pid::from_raw(0),
+        parent_pgid: unistd::Pid::from_raw(0),
+        children: vec![],
+        last_exit_code: 0,
+    }));
+
     // setup symtable
     let mut syms = SymTable::new();
     load_defaults(&mut syms);
     load_environment(&mut syms);
     static_stdlib(&mut syms).unwrap_or_else(|err: String| eprintln!("{}", err));
-    dynamic_stdlib(&mut syms).unwrap_or_else(|err: String| eprintln!("{}", err));
+    // reload this later with the state bindings
+    dynamic_stdlib(&mut syms, None).unwrap_or_else(|err: String| eprintln!("{}", err));
 
     // if there are args those are scripts, run them and exit
     if env::args().count() > 1 {
@@ -100,7 +114,7 @@ fn main() {
         run(cfg_file.clone(), &mut syms)
             .unwrap_or_else(|err: String| eprintln!("failed to load script {}\n{}", cfg_file, err));
     }
-    dynamic_stdlib(&mut syms).unwrap_or_else(|err: String| eprintln!("{}", err));
+    dynamic_stdlib(&mut syms, Some(shell_state_bindings)).unwrap_or_else(|err: String| eprintln!("{}", err));
 
     // setup readline
     let mut rl = Reedline::create();
@@ -134,7 +148,7 @@ fn main() {
 
             Signal::CtrlD  => {
                 println!("EOF!");
-                panic!();
+                return
             },
 
             Signal::CtrlC => {