Can't exit out of endless loop calling builtin

[occivink]

Hi,

If you run while $true { echo a } (or any other builtin in the loop) you'll be stuck in an endless loop.
It looks as though builtin commands can't be interrupted.

[xiaq]

There is a channel that exposes interrupts, but since goroutines cannot be interrupted from outside, we need to insert selects on this channel to ensure that interrupts are respected. For instance, the esleep commands respect interrupts; you can verify this by running esleep 10 and ^C it.

Making sure that each builtin respects interrupts can be a bit tricky, but there is one low-hanging fruit: before the execution of each pipeline, check this channel and if there are interrupt signals, abort the execution.

[xiaq]

Builtin commands are now interruptible.