* ls: add new optional arguments to --classify flag
The --classify flag in ls now takes an option when argument
that may have the values always, auto and none.
Modified clap argument to allow an optional parameter and
changed the classify flag value parsing logic to account for
this change.
* ls: add test for indicator-style, ind and classify with value none
* ls: require option paramter to --classify to use a = to specify flag value
* ls: account for all the undocumented possible values for the --classify flag
Added the other values for the --classify flag along with modifications to tests.
Also documented the inconsistency between GNU coreutils because we accept the
flag value even for the short version of the flag.
The iflag, oflag and conv cli arguments take a list of values
and the correct behavior is to collect all values from multiple
occurences of theme.
For example if we call `dd --iflag=directory --iflag=skip_bytes` this should
collect the two values, `directory` and `skip_bytes` for iflag.
The unittest was added for this case.
Replace `ByteSplitter` and `LineSplitter` with `ByteChunkWriter` and
`LineChunkWriter` respectively. This results in a more maintainable
design and an increase in the speed of splitting by lines.
Correct the `test_split::test_suffixes_exhausted` test case so that it
actually exercises the intended behavior of `split`. Previously, the
test fixture contained 26 bytes. After this commit, the test fixture
contains 27 bytes. When using a suffix width of one, only 26 filenames
should be available when naming chunk files---one for each lowercase
ASCII letter. This commit ensures that the filenames will be exhausted
as intended by the test.
Add the `ByteChunkWriter` and `LineChunkWriter` structs and
implementations, but don't use them yet. This structs offer an
alternative approach to writing chunks of output (contrasted with
`ByteSplitter` and `LineSplitter`). The main difference is that
control of which underlying file is being written is inside the writer
instead of outside.
Add some helper functions and adjust some error-handling to make the
`Output::dd_out()` method, containing the main loop of the `dd`
program, more concise. This commit also adds documentation and
comments describing the main loop procedure in more detail.
