Initial commit

This initial commit has the following:

* We can spawn a terminal.
* Given a new window, we can move it around the screen, but only the
  window that was created, all the other windows disappear on the void,
  so.. :(

and that's it

1 files changed, 47 insertions, 0 deletions

diff --git a/src/command.rs b/src/command.rs
new file mode 100644
index 0000000..ddfa269
--- /dev/null
+++ b/src/command.rs
@@ -0,0 +1,47 @@
+//! Command execution module.
+//!
+use std::ffi::OsStr;
+use std::process::{Command,Child};
+use std::io::{Result, Error, ErrorKind};
+
+use libc::c_int;
+use libc::types::os::arch::posix88::pid_t;
+
+const WNOHANG: c_int = 0x00000001;
+
+extern {
+    /// wait for a child process to stop or terminate.
+    pub fn waitpid(pid: pid_t, stat_loc: *mut c_int, options: c_int) -> pid_t;
+}
+
+/// Extension to the Child struct that allows to check the status without block the
+/// current thread.
+pub trait ChildExt {
+    fn wait_nohang(&mut self) -> Result<bool>;
+}
+
+impl ChildExt for Child {
+    /// Checks if the calling child is a zombie and try to kill it, returning
+    /// if it was killed or not.
+    fn wait_nohang(&mut self) -> Result<bool> {
+        let mut stat = 0i32;
+        let pid = unsafe { waitpid(self.id() as i32, &mut stat, WNOHANG) };
+        if pid < 0 {
+            Err(Error::new(ErrorKind::NotFound, format!("pid not found {}", pid)))
+        } else {
+            if pid > 0 {
+                Ok(self.wait()
+                    .map(|x| {
+                        x.success()
+                    }).unwrap_or(false))
+            } else {
+                Ok(false)
+            }
+        }
+    }
+}
+
+/// Executes the given command.
+pub fn exec_cmd<S: AsRef<OsStr>>(program: S, args: &[S]) -> Result<Child> {
+    Command::new(program).args(args).spawn()
+}