Read flags that refuse a final symlink and never block on a pipe.
`O_NOFOLLOW` is what stops a planted link serving another file's bytes
as ours. `O_NONBLOCK` matters because a synchronous open of a FIFO waits
for a writer that never arrives, stalling the entire process.
Read flags that refuse a final symlink and never block on a pipe.
`O_NOFOLLOW` is what stops a planted link serving another file's bytes as ours. `O_NONBLOCK` matters because a synchronous open of a FIFO waits for a writer that never arrives, stalling the entire process.