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.
Replace the custom `split::walk_lines()` function with a call to
`std::io::copy()`, using a new `TakeLines` reader as the source and
`stdout` as the destination. The `TakeLines` reader is an adaptor that
scans the bytes being read for line ending characters and stops the
reading after a given number of lines has been read (similar to the
`std::io::Take` adaptor).
This change
* makes the `read_n_lines()` function more concise,
* allows it to mirror the implementation of `read_n_bytes()`,
* increases the speed of `head -n NUM`.
Fix a bug in which "\r\n" was not being replaced with "\n" in text mode
on Windows. This would happen only if one call to `write()` ended with a
"\r" character and the next call to `write()` started with a "\n"
character. This commit fixes the bug by buffering a "\r" character if it
appears at the end of one call to `write()` and only writing if the
first character in the next call to `write()` is *not* a "\n" character.
Fixes issue #2681.
Since tac must read its input files completely to start processing them
from the end, it is particularly suited to use memory maps to benefit
from the page cache maintained by the operating systems to bring the
necessary data into memory as required.
This does also include situations where the input is stdin, but not via
a pipe but for example a file descriptor set up by the user's shell
through an input redirection.
