4.5.0
Customizable output format for redirected output
In a natural follow-on to the 4.4.0 redirected-output feature, the
4.5.0 release allows your tap-files to be in a different output
format from the main program output.
For example, using
mlr --icsv --opprint ... then put --ojson 'tee > "mytap-".$a.".dat",
$*' then ...
the input is CSV, the output is pretty-print tabular, but the
tee-files output is written in JSON format. Likewise --ofs, --ors,
--ops, --jvstack, and all other output-formatting options from the
main help at mlr -h and/or man mlr default to the main command-line
options, and may be overridden with flags supplied to mlr put and
mlr tee.
4.4.0
Redirected output, row-value shift, and other features
The principal feature of Miller 4.4.0 is redirected output. Inspired
by awk, Miller lets you tap/tee your data as it's processed, run
output through subordinate processes such as gzip and jq, split a
single file into multiple files per an account-ID column, and so
on.
Details:
http://johnkerl.org/miller/doc/reference.html#Redirected-output_statements_for_put
Other features:
mlr step -a shift allows you to place the previous record's
values alongside the current record's values:
http://johnkerl.org/miller/doc/reference.html#step
mlr head, when used without the group-by flag (-g), stops after
the specified number of records has been output. For example,
even with a multi-gigabyte data file, mlr head -n 10 hugefile.dat
will complete quickly after producing the first ten records
from the file.
The sec2gmtdate verb, and sec2gmtdate function for filter/put,
is new: please see
http://johnkerl.org/miller/doc/reference.html#sec2gmtdate and
http://johnkerl.org/miller/doc/reference.html#Functions_for_filter_and_put.
sec2gmt and sec2gmtdate both leave non-numbers as-is, rather
than formatting them as (error). This is particularly relevant
for formatting nullable epoch-seconds columns in SQL-table
output: if a column value is NULL then after sec2gmt or
sec2gmtdate it will still be NULL.
The dot operator has been universalized to work with any data
type and produce a string. For example, if the field n has
integers, then instead of typing mlr put '$name = "value:".string($n)'
you can now simply domlr put '$name = "value:".$n'. This is
particularly timely for creating filenames for redirected
print/dump/tee/emit output.
The online documents now have a copy of the Miller manpage:
http://johnkerl.org/miller/doc/manpage.html
Bugfix: inside filter/put, $x=="" was distinct from isempty($x).
This was nonsensical; now both are the same.
Use release tarball and drop autotools dependencies.
Changes in 3.4.0:
JSON, reshape, regex captures, and more
Primary features:
JSON is now a supported format for input and output. Miller handles tabular data, and JSON supports arbitrarily deeply nested data structures, so if you want general JSON processing you should use jq. But if you have tabular data represented in JSON then Miller can now handle that for you. Please see the reference page and the FAQ.
Reshape is a standard data-processing idiom, now available in Miller: http://johnkerl.org/miller/doc/reference.html#reshape
Incidentally (not part of this release, but new since the last release) Miller is now available in FreeBSD's package manager: https://www.freshports.org/textproc/miller/. A full list of distributions containing Miller may be found here.
Miller is not yet available from within Fedora/CentOS, but as a step toward this goal, an SRPM is included in this release (see file-list below).
DSL enhancements for mlr put and mlr filter:
Regex captures \0 through \9: http://johnkerl.org/miller/doc/reference.html#Regex_captures
Ternary operator in expression right-hand sides: e.g. mlr put '$y = $x < 0.5 ? 0 : 1'
Boolean literals true and false
Final semicolon is now allowed: e.g. mlr put '$x=1;$y=2;'
Environment variables are now accessible, where environment-variable names may be string literals or arbitrary expressions: mlr put '$home = ENV["HOME"]' or mlr put '$value = ENV[$name]'.
While records are still string-to-string maps for input and output, and between then statements, types are preserved between multiple statements within a put. Example: mlr put '$y = string($x); $z = $y . $y' works as expected, without requring mlr put '$y = string($x); $z = string($y) . string($y)' as before.
Bug fixes:
Mixed-format join, e.g. CSV file joined with DKVP file, was incorrectly computing default separators (IRS, IFS, IPS). This resulted in records not being joined together.
Segmentation violation on non-standard-input read of files with size an exact multiple of page size and not ending in IRS, e.g. newline. (This is less of a corner case than it sounds: for example, leave a long-running program running with output redirected to a file, then in a sleep-and-process loop, have Miller process that file. The former program's stdio library will likely be doing block-sized buffered I/O, where block sizes will often be multiples of system page size and the block will almost surely not ending a newline.)
Acknowledgements: Big thank-yous to @gregfr and @aaronwolen for feature requests including reshape and regex captures, and to @jungle-boogie for his work getting Miller into FreeBSD. Also, ongoing thanks to @0-wiz-0 for his past work on configure support, making it possible for Miller to be put to use in multiple operating systems.
3.3.2
Bootstrap sampling, EWMA, merge-fields, isnull/isnotnull functions
@johnkerl johnkerl released this on Jan 11 · 497 commits to master since this release
Bootstrap sampling in mlr bootstrap: http://johnkerl.org/miller/doc/reference.html#bootstrap. Compare to reservoir sampling in mlr sample: http://johnkerl.org/miller/doc/reference.html#sample.
Exponentially weighted moving averages in mlr step -a ewma: principally useful for smoothing of noisy time series, e.g. finely sampled system-resource utilization to give one of many possible examples. Please see http://johnkerl.org/miller/doc/reference.html#step.
"Horizontal" univariate statistics in mlr merge-fields, compared to mlr stats which is "vertical". Also allows collapsing multiple fields into one, such as in_bytes and out_bytes data fields summing to bytes_sum. This can also be done easily using mlr put. However, mlr merge-fields allows aggregation of more than just a pair of field names, and supports pattern-matching on field names. Please see http://johnkerl.org/miller/doc/reference.html#merge-fields for more information.
isnull and isnotnull functions for mlr filter and mlr put.
stats1, stats2, merge-fields, step, and top correctly handle not only missing fields (in the row-heterogeneous-data case) but also null-valued fields.
Minor memory-management improvements.
Problems found locating distfiles:
Package cabocha: missing distfile cabocha-0.68.tar.bz2
Package convertlit: missing distfile clit18src.zip
Package php-enchant: missing distfile php-enchant/enchant-1.1.0.tgz
Otherwise, existing SHA1 digests verified and found to be the same on
the machine holding the existing distfiles (morden). All existing
SHA1 digests retained for now as an audit trail.
Multi-character RS,FS,PS
You can process CRLF-terminated DKVP files with mlr --dkvp --rs
crlf.
You can process LF-terminated CSV files with mlr --csv --rs lf.
You can process TSV using mlr --fs tab; you can convert TSV to CSV
using mlr --ifs tab --ofs comma.
Along with many more possibilities.
Please see mlr -h for more information.
There is one minor, backward-incompatible change which I felt not
worth calling this 3.0.0: default field separator for NIDX format
is now space, not comma.
Changes:
v2.1.1
Incremental read-performance increase for CSV format
While #51 is still underway, already there is nearly a 2x
read-performance increase in v2.1.1 over v2.1.0.
v2.1.0
Minor enhancements and bug fixes
Highlights: travis-CI integration (thanks @SikhNerd!); hour-minute-second
functions; fixed pretty-print alignment of UTF-8 data.
Miller is like sed, awk, cut, join, and sort for name-indexed data
such as CSV.
With Miller, you get to use named fields without needing to count
positional indices.
This is something the Unix toolkit always could have done, and
arguably always should have done. It operates on key-value-pair
data while the familiar Unix tools operate on integer-indexed
fields: if the natural data structure for the latter is the array,
then Miller's natural data structure is the insertion-ordered hash
map. This encompasses a variety of data formats, including but not
limited to the familiar CSV. (Miller can handle positionally-indexed
data as a special case.)
