This makes clap wrap the help text according to the terminal width,
which improves readability for terminal widths < 120 chars,
because clap defaults to a width of 120 chars without this feature.
`LANGUAGE=C` is not enough, `LC_ALL=C` is needed as the environment
variable that overrides all the other localization settings.
e.g.
```bash
$ LANGUAGE=C id foobar
id: ‘foobar’: no such user
$ LC_ALL=C id foobar
id: 'foobar': no such user
```
* replace `LANGUAGE` with `LC_ALL` as environment variable in the tests
* fix the the date string of affected uutils
* replace `‘` and `’` with `'`
Reorganize the code in `truncate.rs` into three distinct functions
representing the three modes of operation of the `truncate` program. The
three modes are
- `truncate -r RFILE FILE`, which sets the length of `FILE` to match the
length of `RFILE`,
- `truncate -r RFILE -s NUM FILE`, which sets the length of `FILE`
relative to the given `RFILE`,
- `truncate -s NUM FILE`, which sets the length of `FILE` either
absolutely or relative to its curent length.
This organization of the code makes it more concise and easier to
follow.
Create a method that computes the final target size in bytes for the
file to truncate, given the reference file size and the parameter to the
`TruncateMode`.
Add a helper function to contain the code for parsing the size and the
modifier symbol, if any. This commit also changes the `TruncateMode`
enum so that the parameter for each "mode" is stored along with the
enumeration value. This is because the parameter has a different meaning
in each mode.
Remove "read" permissions from the `OpenOptions` when opening a new file
just to truncate it. We will never read from the file, only write to
it. (Specifically, we will only call `File::set_len()`.)
Fix a bug in which the incorrect character was being used to indicate
"round up to the nearest multiple" mode. The character was "*" but it
should be "%". This commit corrects that.
Change the error message for when the reference file (the `-r` argument)
is not found to match GNU coreutils. This commit also eliminates a
redundant call to `File::open`; the file need not be opened because the
size in bytes can be read from the result of `std::fs::metadata()`.
Change the interface provided by the `parse_size()` function to reduce
its responsibilities to just a single task: parsing a number of bytes
from a string of the form '123KB', etc. Previously, the function was
also responsible for deciding which mode truncate would operate in.
Furthermore, this commit simplifies the code for parsing the number and
unit to be less verbose and use less mutable state.
Finally, this commit adds some unit tests for the `parse_size()`
function.
