tty: stop spamming VEOF on raw terminals, and cleanly handle EOF #97
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There is no point in sending VEOF on PTYs that aren't interpreting them. Simply hanging up and letting the session get killed with SIGHUP is the right thing to do.
The old code would loop forever trying to read 0 bytes and thinking that the input fd was read-ready. This is normally not an issue, but because we're emulating regular files as eventfds (since epoll won't support them), things like bst --tty cat </dev/null would never terminate.
mstory21
approved these changes
Jun 28, 2024
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This PR contains two changes:
The first one is a change in how we handle hangups from stdin; if the child pty is not in raw mode (or rather, is in non-canonical mode), and therefore isn't interpreting VEOF, then we won't send any. Instead, we now just hang up the terminal, which causes the session to die with a SIGHUP.
The second fixes a weirdity I noticed where we would not handle EOF properly, and commands like
bst --tty cat </dev/nullwould not terminate.