Merge pull request #7 from jonas-schievink/popen

Enable `io.popen` on Linux

build.rs

@@ -1,8 +1,17 @@
 extern crate gcc;
 
+use std::env;
+
 fn main() {
-    gcc::Config::new()
-        .define("LUA_USE_APICHECK", None)
+    let mut config = gcc::Config::new();
+
+    if env::var("CARGO_CFG_TARGET_OS") == Ok("linux".to_string()) {
+        // Among other things, this enables `io.popen` support.
+        // Despite the name, we could enable this on more platforms.
+        config.define("LUA_USE_LINUX", None);
+    }
+
+    config.define("LUA_USE_APICHECK", None)
         .include("lua")
         .file("lua/lapi.c")
         .file("lua/lauxlib.c")

examples/repl.rs

@@ -0,0 +1,40 @@
+//! This example shows a simple read-evaluate-print-loop (REPL).
+
+extern crate rlua;
+
+use rlua::*;
+use std::io::prelude::*;
+use std::io::{stdin, stdout, stderr, BufReader};
+
+fn main() {
+    let lua = Lua::new();
+    let mut stdout = stdout();
+    let mut stdin = BufReader::new(stdin());
+
+    loop {
+        write!(stdout, "> ").unwrap();
+        stdout.flush().unwrap();
+
+        let mut line = String::new();
+
+        loop {
+            stdin.read_line(&mut line).unwrap();
+
+            match lua.eval::<LuaMultiValue>(&line) {
+                Ok(values) => {
+                    println!("{}", values.iter().map(|value| format!("{:?}", value)).collect::<Vec<_>>().join("\t"));
+                    break;
+                }
+                Err(LuaError(LuaErrorKind::IncompleteStatement(_), _)) => {
+                    // continue reading input and append it to `line`
+                    write!(stdout, ">> ").unwrap();
+                    stdout.flush().unwrap();
+                }
+                Err(e) => {
+                    writeln!(stderr(), "error: {}", e).unwrap();
+                    break;
+                }
+            }
+        }
+    }
+}