musl - musl - an implementation of the standard library for Linux-based systems

isatty: don't collapse all non-EBADF errors to ENOTTY

linux puts hung-up ttys in a state where ioctls produce EIO, and may do the same for other types of devices in error or shutdown states. such an error clearly does not mean the device is not a tty, but it also can't reliably establish that the device is a tty, so the only safe thing to do seems to be reporting the error. programs that don't check errno will conclude that the device is not a tty, which is no different from what happens now, but at least they gain the option to differentiate between the cases. commit c84971995b3a6d5118f9357c040572f4c78bcd55 introduced the errno collapsing behavior, but prior to that, errno was not set at all by isatty.

Diffstat (limited to 'src')

1 files changed, 2 insertions, 4 deletions