Instead of using a BufReader and reading each line separately,
allocating a String for each one, we read to a chunk. Lines are
references to this chunk. This makes the allocator's job much easier
and yields performance improvements.
Chunks are read on a separate thread to further improve performance.
Fix a bug in which `head` failed to print headings for `stdin` inputs
when reading from multiple files, and fix another bug in which `head`
failed to print a blank line between the contents of a file and the
heading for the next file when reading multiple files. The output now
matches that of GNU `head`.
Change the error messages that get printed to `stderr` for compatibility
with GNU `wc` when an input is a directory and when an input does not
exist.
Fixes#2211.
This closes#2181.
`who --lookup` is failing with a runtime panic (double free).
Since `crate::dns-lookup` already includes a safe wrapper for `getaddrinfo`
I used this crate instead of further debugging the existing code in
utmpx::canon_host().
* It was neccessary to remove the version constraint for libc in uucore.
Refactor code from the `backwards_thru_file()` function into a new
`ReverseChunks` iterator, and use that iterator to simplify the
implementation of the `backwards_thru_file()` function. The
`ReverseChunks` iterator yields `Vec<u8>` objects, each of which
references bytes of a given file.