Collect structs, implementations, and functions that have to do with
reporting number of blocks read and written into their own new module,
`progress.rs`. This commit also adds docstrings for everything and
unit tests for the significant methods. This commit does not change
the behavior of `dd`, just the organization of the code to make it
more maintainable and testable.
Prevent `dd` from terminating with an error when given the
command-line argument `of=/dev/null`. This commit allows the call to
`File::set_len()` to result in an error without causing the process to
terminate prematurely.
- Configured clap to take crate version, so version is now visible in docs.
- Added ABOUT string from expr help output, so about section is getting rendered in docs.
- Added USAGE section.
- Added HELP section for each args.
Place the "truncated records" line below the "records out" line in the
status report produced by `dd` and properly handle the singularization
of the word "record" in the case of 1 truncated record. This matches
the behavior of GNU `dd`.
For example
$ printf "ab" | dd cbs=1 conv=block status=noxfer > /dev/null
0+1 records in
0+1 records out
1 truncated record
$ printf "ab\ncd\n" | dd cbs=1 conv=block status=noxfer > /dev/null
0+1 records in
0+1 records out
2 truncated records
Add the `-e` flag, which indicates whether to elide (that is, remove)
empty files that would have been created by the `-n` option.
The `-n` command-line argument gives a specific number of chunks into
which the input files will be split. If the number of chunks is
greater than the number of bytes, then empty files will be created for
the excess chunks. But if `-e` is given, then empty files will not be
created.
For example, contrast
$ printf 'a\n' > f && split -e -n 3 f && cat xaa xab xac
a
cat: xac: No such file or directory
with
$ printf 'a\n' > f && split -n 3 f && cat xaa xab xac
a
Add support for the `-x` command-line option to `split`. This option
causes `split` to produce filenames with hexadecimal suffixes instead
of the default alphabetic suffixes.
Add a `NumericHexadecimal` member to the `SuffixType` enum so that a
future commit can add support for hexadecimal filename suffixes to the
`split` program.
Refactor the code to use a `SuffixType` enumeration with two members,
`Alphabetic` and `NumericDecimal`, representing the two currently
supported ways of producing filename suffixes. This prepares the code
to more easily support other formats, like numeric hexadecimal.
Clean up unit tests in the `dd` crate to make them easier to
manage. This commit does a few things.
* move test cases that test the complete functionality of the `dd`
program from the `dd_unit_tests` module up to the
`tests/by-util/test_dd.rs` module so that they can take advantage of
the testing framework and common testing tools provided by uutils,
* move test cases that test internal functions of the `dd`
implementation into the `tests` module within `dd.rs` so that they
live closer to the code they are testing,
* replace test cases defined by macros with test cases defined by
plain old functions to make the test cases easier to read at a
glance.
Add helper method `CmdResult::stdout_is_fixture_bytes()`, which is
like `stdout_is_fixture()` but compares stdout to the raw bytes of a
given file instead of decoding the contents of the file to a UTF-8
string.
