add --passive option for backgrounding

[FND]

It appears rerun doesn't like to be backgrounded:

$ bundle exec rerun "bundle exec ruby app.rb" &
[rerun] App launched
stty: standard input: Inappropriate ioctl for device
stty: standard input: Inappropriate ioctl for device
stty: standard input: Inappropriate ioctl for device
stty: standard input: Inappropriate ioctl for device
<ad infinitum>

Presumably that's happening within the key_pressed method when attempting to read STDIN.

Thus this new --passive option* disables the on-the-fly commands entirely.

* not sure whether -b is a good short variant, but -p was taken

[alexch]

Maybe --background would be a better name, then?

Good catch. btw on OS X i get somewhat different (still broken) backgrounding behavior from the unpatched version: it immediately pauses, then foregrounding shows stty: tcsetattr: Interrupted system call

[FND]

--background was my first thought as well, but that seemed misleading as it suggests automatic backgrounding/daemonization.

(I should have mentioned I'm on Arch Linux and Ruby 1.9.3)

[alexch]

Yeah, good point. There's a similar terminological knot around the --exit (-x) option -- it doesn't make rerun exit, it makes it expect that its target program will exit.

Maybe --no-input?

Hopefully I'll be more clever after a cup of coffee.

[FND]

I suppose --no-input would work - not sure if it's less confusing than --passive, but in the end, anyone who looks for this probably already knows why they need it.

[alexch]

--deaf ?
--no-listen ?

[FND]

Since we're clearly having trouble describing this option, here's another thought: Auto-detect whether the process was backgrounded.

Not sure how that could be done - but perhaps there's some check on $stdin we could perform?

[alexch]

http://www.unixguide.net/unix/faq/3.7.shtml

I think I have tty-detecting code in Wrong somewhere...

[alexch]

Hmph. On OS X, in a backgrounded process, STDIN.tty? returns true. Back to
the drawing board...

[FND]

Same on my Linux machine, which kinda makes sense because it's still attached to the terminal - what we want is to determine whether we're running interactively, which I haven't found a solution for yet.

[alexch]

I looked into Highline, which reportedly [1] was the cleanest way to do this, and found that a recent commit [2] inadvertently removed the feature [3].

[1] http://stackoverflow.com/questions/174933/how-to-get-a-single-character-without-pressing-enter/3983726#3983726
[2] JEG2/highline@2abb2c7#lib/highline/system_extensions.rb
[3] JEG2/highline#50

[envygeeks]

I kinda need this in a sorts, when I open up a Pry session in the middle of a live HTTP session the polling for c, r and other friends makes it impossible to work with Pry (not to mention the fact that I can't use c and r without the system assuming I want to restart,) so much so I had to program my own watcher even though I would rather work with Rerun because it probably thinks about stuff I don't care about (I just kill everything and restart it.)

Just an option to entirely disable the c, r and other polling would suffice to making this happy, edit: or... maybe you could do like Guard did and integrate with Pry (not saying it's a great idea but who wouldn't love a side debugger to test things out quickly) and just make c, r and others commands inside of Pry.

[jipiboily]

👍

I started to use rerun in a proof of concept project and it works great but I feel the same pain as @envygeeks. Is there a chance that this will be merged at some point (no rush, I can use the fork for now)? 😄

[alexch]

Yeah, I'll take care of it today.

[alexch]

I think I will go back to --background. To my ear, it doesn't sound like it implies automatic daemonization... that would be --daemonize or some such. And it makes -b make more sense :-)

[FND]

Sounds good - done > perfect etc.

[jipiboily]

Didn't want to rush you, but thanks! :)

👍

[alexch]

It was my pleasure. I've been learning iOS and working in Ruby for a few hours was a welcome relief. I'll push it as soon as RubyGems.org is back online (see http://news.ycombinator.com/item?id=5139583 ).