Make popd and pushd update PWD to fix issue #683

Synchronize Redox and Unix job_control

Add tests to #638 array parsing issue

cases array length is 0 or 1.

Change: remove tests dependency

Move binary::main into actual main

CD_CHANGE function

script_exec test is depends on examples/a* and examples/b*.
If we try to change tests in a* or b*, we must change
script_exec.out
So, I remove dependency.

Fix to array parsing issue 

Glob_check was incorporating one element arrays into globs. The fix simply checks if the b']' is not succeeded by another character, which would make it a glob

Clean up builtin isatty

Fix issue board link

Update redox-syscall, use WUNTRACED for waitpid in Redox

Call execve from fork_and_exec in sys/redox.rs so they can share code

Sag0Sag0 authored 7 years ago and Michael Aaron Murphy committed 7 years ago

* Add builtin isatty

* Attempt fix for redox specific error

* Add documentation on platform specific stuff

Found some issues with pipeline execution logic, foreground job control, and background job control, and so I've fixed them and added a new integration test. The following use cases are now working:

```
echo foo | grep foo && echo found foo
echo foo | grep bar || echo did not find bar
echo test | grep test && echo found test | cat
```

More Foreground Job Control Improvements

Fix for double quote parsing

Job control in Ion was a complete mess, and it was a wonder that it even worked at one point to begin with! I've gone through and fixed a number of issues related to foreground job management.

- Processes are no longer preemptively killed by Ion to emulate SIGPIPE support.
- Processes within a pipeline are now assigned the same PGID.
- A SIGPIPE handler is now registered so that processes exit when they receive a SIGPIPE.
- Jobs should exit with the correct exit statuses in more situations.
- External commands now use fork + exec, rather than `std::process::Command`.
- Redox's foreground job management was also improved.
- Some refactoring was performed, with more refactoring planned in the future.

There's likely some issues that remain to be addressed though. Needs more testing & bug reports. Background job management remains to be mostly broken for now, so that's an area to look into next.