It is probably too hard to verify that the sync is actually performed,
so we just check that we have a test using the code path, pro forma.
Signed-off-by: anastygnome <noreplygitemail@protonmail.com>
Add a unit test for combining the directory given in `--tmpdir` with
any subdirectory structure appearing in the prefix of the template
string. For example,
$ mktemp --tmpdir=a b/cXXX
a/b/cNqJ
This behavior is currently working, but a unit test was missing.
Fix a bug in which `mktemp` would replace everything in the template
argument from the first 'X' to the last 'X' with random bytes, instead
of just replacing the last contiguous block of 'X's.
Before this commit,
$ mktemp XXX_XXX
2meCpfM
After this commit,
$ mktemp XXX_XXX
XXX_Rp5
This fixes test cases `suffix2f` and `suffix2d` in
`tests/misc/mktemp.pl` in the GNU coreutils test suite.
Simplify the logic of computing the file path parameters (the
directory, prefix, suffix, and number of random characters) for the
temporary file created by `mktemp`. This commits adds an `Options`
struct as a layer of indirection between the application logic and
`clap`, and a `Params` struct whose associated function is responsible
for determining the file path parameters from the `Options`. This is
an improvement because the previous code had some logic for
determining file path parameters in one place and some in another
place.
Show the "total" label in the "source" column or in the "target"
column if the "source" column is not visible.
Before this commit,
$ df --total --output=target .
Mounted on
/
-
After this commit,
$ df --total --output=target .
Mounted on
/
total
Include the suffix in the error message produced by `mktemp` when
there are too few Xs in the template. Before this commit,
$ mktemp --suffix=X aXX
mktemp: too few X's in template 'aXX'
After this commit,
$ mktemp --suffix=X aXX
mktemp: too few X's in template 'aXXX'
This matches the behavior of GNU `mktemp`.
Correct the error message when the template argument contains a path
separator in its suffix. Before this commit:
$ mktemp aXXX/b
mktemp: too few X's in template 'b'
After this commit:
$ mktemp aXXX/b
mktemp: invalid suffix '/b', contains directory separator
This error message is more appropriate and matches the behavior of GNU
mktemp.
On macOS path.is_dir() can be false for directories
if it was a redirect, e.g. ` tail < DIR`
* fix some tests for macOS
Cleanup:
* fix clippy/spell-checker
* fix build for windows by refactoring stdin_is_pipe_or_fifo()
Correct the error message produced by `mktemp` when `--tmpdir` is
given and the template is an absolute path:
$ mktemp --tmpdir=a /XXX
mktemp: invalid template, '/XXX'; with --tmpdir, it may not be absolute
* add various tests adapted from `gnu/tests/tail-2/follow-stdin.sh`
* explicitly set_stdin to null where needed, otherwise stdin is always
`piped`
* tighten some existing tests (no_stderr, code_is, etc)
* add test for fifo
* add various tests adapted from `gnu/tests/tail-2/follow-stdin.sh`
* explicitly set_stdin to null where needed, otherwise stdin is always
`piped`
* tighten some existing tests (no_stderr, code_is, etc)
* add test for fifo
On Android and macOS all/some tests for stdin fail with:
`cannot stat '-': No such file or directory`
Apparently the `/dev/stdin` redirect workaround doesn't work for
these targets.
Update `chown` to allow setting the owner of a file to a numeric user
ID regardless of whether a corresponding username exists on the
system.
For example,
$ touch f && sudo chown 12345 f
succeeds even though there is no named user with ID 12345.
Fixes#3380.
Correct the error that arises from a path separator in the prefix
portion of a template argument provided to `mktemp`. Before this
commit, the error message was incorrect:
$ mktemp -t a/bXXX
mktemp: failed to create file via template 'a/bXXX': No such file or directory (os error 2) at path "/tmp/a/bege"
After this commit, the error message is correct:
$ mktemp -t a/bXXX
mktemp: invalid template, 'a/bXXX', contains directory separator
The code was failing to check for a path separator in the prefix
portion of the template.
When using left-justify with integer conversion (like `printf '%-o'`),
default the minimum width to 1.
Closes: https://github.com/uutils/coreutils/issues/3050
Signed-off-by: Hanif Ariffin <hanif.ariffin.4326@gmail.com>
Fix a bug in `mktemp` where it was not respecting the path given by
the positional argument. Previously, it would place the temporary file
whose name is induced by a given template in the `/tmp` directory,
like this:
$ mktemp XXX
/tmp/LJr
$ mktemp d/XXX
/tmp/d/IhS
After this commit, it respects the directory given in the template
argument:
$ mktemp XXX
LJr
$ mktemp d/XXX
d/IhS
Fixes#3440.
* Fix a timing related bug with polling (---disable-inotify) where some
Events weren't delivered fast enough by `Notify::PollWatcher` to pass all
of tests/tail-2/retry.sh and test_tail::{test_retry4, retry7}.
* uu_tail now reverts to polling automatically if inotify backend reports
too many open files (this mimics the behavior of GNU's tail).
This makes uu_tail pass the "gnu/tests/tail-2/inotify-only-regular" test
again by adding support for charater devices.
test_tail:
* add test_follow_inotify_only_regular
* add clippy fixes for windows
The code for creating a Passwd from the fields of the raw syscall result
assumed that the syscall would return valid C strings in all non-error
cases. This is not true, and at least one platform (Android) will
populate the fields with null pointers where they are not supported.
To fix this and prevent the error from happening again, this commit
changes `cstr2string(ptr)` to check for a null pointer, and return an
`Option<String>`, with `None` being the null pointer case. While
arguably it should be the caller's job to check for a null pointer
before calling (since the safety precondition is that the pointer is to
a valid C string), relying on the type checker to force remembering this
edge case is safer in the long run.
Add a missing dash to the `--total` argument applied in the
`test_df_output` test case. Before this commit, the argument `-total`
was treated as a path argument. After this commit, `--total` is
treated as a command-line option that causes the total file usage to
be displayed.
* hashsum: add --no-names option from official b3sum tool
The official b3sum tool has a --no-names option for only printing the
hashes, omitting the filenames. This is quite handy when used from
scripts because it spares the postprocessing with "cut" or "awk".
Since the installed b3sum symlink would also serve as a drop-in for the
official tool, the --no-names option is expected to exist for
compatibility.
Add a --no-names option not only for b3sum but for hashsum in general
(and maybe GNU coreutils will also feel inspired to add this option).
Closes https://github.com/uutils/coreutils/issues/3360
Change formula from: "Used/Size * 100" to "Used/(Used + Avail) * 100".
This formula also works if "Used" and "Avail" do not add up to "Size",
which is the case if there are reserved disk blocks.
When doing
ln b b~
ln -f --b=simple a b
First, we create a backup of b
Then, we force the override of a => b but we make sure that the backup is
done.
So, we had a bug in the ordering of the actions.
we were first removing b. Therefore, losing the capability to do a backup of this.
Change formula from: "Used/Size * 100" to "Used/(Used + Avail) * 100".
This formula also works if "Used" and "Avail" do not add up to "Size",
which is the case if there are reserved disk blocks.
Previously, individual file sizes were used to compute the number width, which
would cause misalignment when the total has a greater number of digits, and is
different from the behavior of GNU wc
```
$ ./target/debug/wc -w -l -m -c -L deny.toml GNUmakefile
95 422 3110 3110 85 deny.toml
349 865 6996 6996 196 GNUmakefile
444 1287 10106 10106 196 total
$ wc -w -l -m -c -L deny.toml GNUmakefile
95 422 3110 3110 85 deny.toml
349 865 6996 6996 196 GNUmakefile
444 1287 10106 10106 196 total
```
"df --output ." was treated as "df --output=." and hence "." was
interpreted as a column name. With this commit, "." is treated as
an argument on its own.
Fixes#3324
Print a usage error when duplicat column names are specified to the
`--output` command-line argument. For example,
$ df --output=source,source
df: option --output: field ‘source’ used more than once
Try 'df --help' for more information.
Implement the "File" column in the `df` output table. Before this
commit, a blank entry appeared in the "File" column for each
row. After this commit, a "-" entry appears when `df` is run with no
positional arguments and the filename appears when run with positional
arguments. For example:
$ touch a b c && df --output=target,file a b c
Mounted on File
/ a
/ b
/ c
Produce a usage error on an invalid signal argument. For example,
$ timeout --signal=invalid 1 sleep 0
timeout: 'invalid': invalid signal
Try 'timeout --help' for more information.
Return an error when a negative interval is provided as the argument
to `uucore::parse_time::from_str()`, since a `Duration` should only be
non-negative.
Fix a bug in the behavior of `split -e -n NUM` when the input file is
empty. Previously, it would panic due to overflow when subtracting 1
from 0. After this change, it will terminate successfully and produce
no output chunks.
Use `Duration::saturating_mul()` to avoid a panic due to overflow in
`uucore::parse_time::from_str()`. This change prevents panic on very
large arguments to timeout and sleep.
These are the first half of changes needed to pass the dd/bytes.sh tests:
- Add iseek and oseek options (additive with skip and seek options)
- Implement tests for the new flags, matching those from dd/bytes.sh
Implement distributing lines of a file in a round-robin manner to a
specified number of chunks. For example,
$ (seq 1 10 | split -n r/3) && head -v xa[abc]
==> xaa <==
1
4
7
10
==> xab <==
2
5
8
==> xac <==
3
6
9
Previously, given 'cp -P a b', where 'a' and 'b' were both symlinks, cp
would end up replacing the target of 'b'.
Signed-off-by: Ryan Gonzalez <ryan.gonzalez@collabora.com>
Fix a bug where `timeout --preserve-status` was not correctly
preserving the status code of the child process if it timed out. When
that happens, the status code of the child process is considered to be
the signal number (in this case, `SIGTERM`). The exit status of
`timeout` is then 128 plus the numeric code associated with `SIGTERM`.
* Adds support for mount path prefix matching and input path
canonicalization
- Sorts mount paths in reverse lexicographical order
- Canonicalize all paths and clear invalid paths
- Checking of mount path prefix matches input path
Implement the `--line-bytes` option to `split`. In this mode, the
program tries to write as many lines of the input as possible to each
chunk of output without exceeding a specified byte limit. The new
`LineBytesChunkWriter` struct represents this functionality.
Implement the `--output` command-line argument, which allows
specifying an exact sequence of columns to display in the output
table. For example,
$ df --output=source,fstype | head -n3
Filesystem Type
udev devtmpfs
tmpfs tmpfs
(The spacing does not exactly match the spacing of GNU `df` yet.)
Fixes#3057.
Correct the column header printed by `df` when the `--block-size`
argument has a value that is a multiple of 1024. After this commit,
the header looks like "1K" or "4M" or "117G", etc., depending on the
particular value of the block size. For example:
$ df --block-size=1024 | head -n1
Filesystem 1K-blocks Used Available Use% Mounted on
$ df --block-size=2048 | head -n1
Filesystem 2K-blocks Used Available Use% Mounted on
$ df --block-size=3072 | head -n1
Filesystem 3K-blocks Used Available Use% Mounted on
$ df --block-size=4096 | head -n1
Filesystem 4K-blocks Used Available Use% Mounted on
Add support for the `--total` option to `df`, which displays the total
of each numeric column. For example,
$ df --total
Filesystem 1K-blocks Used Available Use% Mounted on
udev 3858016 0 3858016 0% /dev
...
/dev/loop14 63488 63488 0 100% /snap/core20/1361
total 258775268 98099712 148220200 40% -
Implement `-n l/k/N` option, where the `k`th chunk of the input file
is written to stdout. For example,
$ seq -w 0 99 > f; split -n l/3/10 f
20
21
22
23
24
25
26
27
28
29
Add support for `split -n l/NUM`. Previously, `split` only supported
`-n NUM`, which splits a file into `NUM` chunks by byte. The `-n
l/NUM` strategy splits a file into `NUM` chunks without splitting
lines across chunks.
https://github.com/uutils/coreutils/pull/3084 (2a333ab391) had some
missing coverage and was merged before I had a chance to fix it.
This PR adds some coverage / improved error messages that were missing
from that previous PR.
If `conv=block,sync` command-line arguments are given and there is at
least one partial record read from the input (for example, if the
length of the input is not divisible by the value of the `ibs`
argument), then output an extra block of `cbs` spaces.
For example, no extra spaces are printed in this example because the
input is of length 10, a multiple of `ibs`:
$ printf "012\nabcde\n" \
> | dd ibs=5 cbs=5 conv=block,sync status=noxfer \
> && echo $
012 abcde$
2+0 records in
0+1 records out
But in this example, 5 extra spaces are printed because the length of
the input is not a multiple of `ibs`:
$ printf "012\nabcdefg\n" \
> | dd ibs=5 cbs=5 conv=block,sync status=noxfer \
> && echo $
012 abcde $
2+1 records in
0+1 records out
1 truncated record
The number of spaces printed is the size of the conversion block,
given by `cbs`.
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.
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
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.
* include io-blksize parameter
* format changes for including io-blksize
Co-authored-by: DevSabb <devsabb@local>
Co-authored-by: Sylvestre Ledru <sylvestre@debian.org>
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.
Correct the accounting for partial records written by `dd` to the
output file. After this commit, if fewer than `obs` bytes are written,
then that is counted as a partial record. For example,
$ printf 'abc' | dd bs=2 status=noxfer > /dev/null
1+1 records in
1+1 records out
That is, one complete record and one partial record are read from the
input, one complete record and one partial record are written to the
output. Previously, `dd` reported two complete records and zero
partial records written to the output in this case.
Change the `filter_mount_list()` function so that it always produces
the same order of `MountInfo` objects. This change ultimately results
in `df` printing its table of filesystems in the same order on each
execution. Previously, the table was in an arbitrary order because the
`MountInfo` objects were read from a `HashMap`.
Fixes#3086.
* 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.
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.
Show a warning if the `skip=N` command-line argument would cause `dd`
to skip past the end of the input. For example:
$ printf "abcd" | dd bs=1 skip=5 count=0 status=noxfer
'standard input': cannot skip to specified offset
0+0 records in
0+0 records out
Show a warning when a block size includes "0x" since this is
ambiguous: the user may have meant "multiply the next number by zero"
or they may have meant "the following characters should be interpreted
as a hexadecimal number".
When specifying `seek=N` and *not* specifying `conv=notrunc`, truncate
the output file to `N` blocks instead of truncating it to zero before
starting to write output. For example
$ printf "abc" > outfile
$ printf "123" | dd bs=1 skip=1 seek=1 count=1 status=noxfer of=outfile
1+0 records in
1+0 records out
$ cat outfile
a2
Fixes#3068.
When this option is present, the files argument is not processed. This option processes the file list from provided file, splitting them by the ascii NUL (\0) character. When files0-from is '-', the file list is processed from stdin.
Using this escaped character will cause `printf` to stop generating characters.
For instance,
```rust
hbina@akarin ~/g/uutils (hbina-add-test-for-additional-escape)> cargo run --quiet -- printf "%s\c%s" a b
a⏎
```
Signed-off-by: Hanif Ariffin <hanif.ariffin.4326@gmail.com>
* test_sort: Output sorted files to a file with different name
Signed-off-by: Hanif Bin Ariffin <hanif.ariffin.43262@gmail.com>
* Fix the test by saving the environment variable
Signed-off-by: Hanif Bin Ariffin <hanif.ariffin.43262@gmail.com>
Co-authored-by: Hanif Bin Ariffin <hanif.ariffin.43262@gmail.com>
This avoids hacking around the short options of these command line
arguments that have been introduced by clap. Additionally, we test and
correctly handle the combination of both version and help. The GNU
binary will ignore both arguments in this case while clap would perform
the first one. A test for this edge case was added.
This allows for `-t` to take invalid unicode (but still single-byte) values
on unix-like platforms. Other platforms, which as of the time of this commit
do not support `OsStr::as_bytes()`, could possibly be supported in the future,
but would require design decisions as to what that means.
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.
Change a word in the error message displayed when an increment value
of 0 is provided to `seq`. This commit changes the message from "Zero
increment argument" to "Zero increment value" to match the GNU `seq`
error message.
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.
Add support for the `-f FORMAT` option to `seq`. This option instructs
the program to render each value in the generated sequence using a
given `printf`-style floating point format. For example,
$ seq -f %.2f 0.0 0.1 0.5
0.00
0.10
0.20
0.30
0.40
0.50
Fixes issue #2616.
Fix a bug where `tail -f` would terminate with an error due to failing
to parse a UTF-8 string from a sequence of bytes read from the
followed file. This commit replaces the call to `BufRead::read_line()`
with a call to `BufRead::read_until()` so that any sequence of bytes
regardless of encoding can be read.
Fixes#1050.
Correct the behavior of `dd` with the `status=noxfer` option. Before
this commit, the status output was entirely suppressed (as happens
with `status=none`). This was incorrect behavior. After this commit,
the input/output counts are printed to stderr as expected.
For example,
$ printf "" | dd status=noxfer
0+0 records in
0+0 records out
This commit also updates a unit test that was enforcing the wrong
behavior.
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).
Fix a bug when getting all but the first NUM lines or bytes of a file
via `tail -n +NUM <file>` or `tail -c +NUM <file>`. The bug only
existed when a file is given as an argument; it did not exist when the
input data came from stdin.
Support `-z` option when the input is not a seekable file. Previously,
the option was accepted by the argument parser, but it was being
ignored by the application logic.
This expands the error message that is printed if either input file has
an unsorted line. Both the program name (join) and the offending line
are printed out with the message to match the behaviour of the GNU
utility.
This commit replaces generic Results with UResults in some key
functions in numfmt. As a result of this, we can provide different
exit codes for different errors, which resolves ~70 failing test
cases in the GNU numfmt.pl test suite.
Fix two issues with the filename creation algorithm. First, this
corrects the behavior of the `-a` option. This commit ensures a
failure occurs when the number of chunks exceeds the number of
filenames representable with the specified fixed width:
$ printf "%0.sa" {1..11} | split -d -b 1 -a 1
split: output file suffixes exhausted
Second, this corrects the behavior of the default behavior when `-a`
is not specified on the command line. Previously, it was always
settings the filenames to have length 2 suffixes. This commit corrects
the behavior to follow the algorithm implied by GNU split, where the
filename lengths grow dynamically by two characters once the number of
chunks grows sufficiently large:
$ printf "%0.sa" {1..91} | ./target/debug/coreutils split -d -b 1 \
> && ls x* | tail
x81
x82
x83
x84
x85
x86
x87
x88
x89
x9000
* print error in the correct order by flushing the stdout buffer before printing an error
* print correct GNU error codes
* correct formatting for config.inode, and for dangling links
* correct padding for Format::Long
* remove colors after the -> link symbol as this doesn't match GNU
* correct the major, minor #s for char devices, and correct padding
* improve speed for all metadata intensive ops by not allocating metadata unless in a Sort mode
* new tests, have struggled with how to deal with stderr, stdout ordering in a test though
* tried to implement UIoError, but am still having issues matching the formatting of GNU
Co-authored-by: electricboogie <32370782+electricboogie@users.noreply.github.com>
Fix a bug in which a negative decimal input would not be displayed with
the correct width in the output. Before this commit, the output was
incorrectly
$ seq -w -.1 .1 .11
-0.1
0.0
0.1
After this commit, the output is correctly
$ seq -w -.1 .1 .11
-0.1
00.0
00.1
The code was failing to take into account that the input decimal "-.1"
needs to be displayed with a leading zero, like "-0.1".
Pad infinity and negative infinity values with spaces when using the
`-w` option to `seq`. This corrects the behavior of `seq` to match that
of the GNU version:
$ seq -w 1.000 inf inf | head -n 4
1.000
inf
inf
inf
Previously, it incorrectly padded with 0s instead of spaces.
* seq: use BigDecimal to represent floats
Use `BigDecimal` to represent arbitrary precision floats in order to
prevent numerical precision issues when iterating over a sequence of
numbers. This commit makes several changes at once to accomplish this
goal.
First, it creates a new struct, `PreciseNumber`, that is responsible for
storing not only the number itself but also the number of digits (both
integer and decimal) needed to display it. This information is collected
at the time of parsing the number, which lives in the new
`numberparse.rs` module.
Second, it uses the `BigDecimal` struct to store arbitrary precision
floating point numbers instead of the previous `f64` primitive
type. This protects against issues of numerical precision when
repeatedly accumulating a very small increment.
Third, since neither the `BigDecimal` nor `BigInt` types have a
representation of infinity, minus infinity, minus zero, or NaN, we add
the `ExtendedBigDecimal` and `ExtendedBigInt` enumerations which extend
the basic types with these concepts.
* fixup! seq: use BigDecimal to represent floats
* fixup! seq: use BigDecimal to represent floats
* fixup! seq: use BigDecimal to represent floats
* fixup! seq: use BigDecimal to represent floats
* fixup! seq: use BigDecimal to represent floats
GNU rm allows the `-r` flag to be specified multiple times, but
uutils/coreutils would previously exit with an error.
I encountered this while attempting to run `make clean` on the
Postgres source tree (github.com/postgres/postgres).
Updates #1663.
This makes uu_tail pass the "gnu/tests/tail-2/descriptor-vs-rename" test.
* add tests for descriptor-vs-rename (with/without verbose)
* fix some minor error messages
* Change data structure from Vec to HashMap in order to better
keep track of files while watching them with `--follow=name`.
E.g. file paths that were removed while watching them and exit
if no files are remaining, etc.
* Move all logic related to file handling into a FileHandling trait
* Simplify handling of the verbose flag.
Replace two loops that print leading and trailing 0s when printing a
number in fixed-width mode with a single call to `write!()` with the
appropriate formatting parameters.
Ensure that the `print_seq_integers()` function is called when the first
number and the increment are integers, regardless of the type of the
last value specified.
Change the way `seq` computes the number of digits needed to print a
number so that it works for inputs given in scientific notation.
Specifically, this commit parses the input string to determine whether
it is an integer, a float in decimal notation, or a float in scientific
notation, and then computes the number of integral digits and the number
of fractional digits based on that. This also supports floating point
negative zero, expressed in both decimal and scientific notation.
