Prevent usize underflow when reducing the size of a file by more than
its current size. For example, if `f` is a file with 3 bytes, then
truncate -s-5 f
will now set the size of the file to 0 instead of causing a panic.
Improve the error message that gets printed when a directory does not
exist. After this commit, the error message is
truncate: cannot open '{file}' for writing: No such file or directory
where `{file}` is the name of a file in a directory that does not
exist.
Add an error for division by zero. Previously, running `truncate -s /0
file` or `-s %0` would panic due to division by zero. After this
change, it writes an error message "division by zero" to stderr and
terminates with an error code.
Fix the behavior of truncate when given a non-existent file so that it
correctly creates the file before truncating it (unless the
`--no-create` option is also given).
`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 `'`
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.
