App::RecordStream - recs - A system for command-line analysis of data
A set of programs for creating, manipulating, and outputting a stream of Records, or JSON hashes. Inspired by Monad.
The quickest way to start using recs is via the minimal, standalone bundle:
curl -fsSL https://recs.pl > recs
chmod +x recs
./recs --help
This is also known as the "fatpacked" recs.
You can also install recs from CPAN as App::RecordStream:
cpanm --interactive App::RecordStream
Using cpanm in interactive mode will prompt you for optional feature support. Other CPAN clients such as cpan and cpanp also work fine, but you can't opt to use any optional features (just like cpanm in non-interactive mode). A kitchen-sink install of App::RecordStream looks like:
cpanm --with-recommends --with-all-features App::RecordStream
If you don't have cpanm itself, you can install it easily with:
curl -fsSL https://cpanmin.us | perl - App::cpanminus
The recs system consists of three basic sets of commands:
- Input commands responsible for generating streams of record objects
- Manipulation commands responsible for analyzing, selecting, and manipulating records
- Output commands responsible for taking record streams and producing output for humans or other programs
These commands can interface with other systems to retrieve data, parse existing files, or just regex out some values from a text stream.
Commands are run using recs command [options and arguments]
. If you're using
a CPAN-based install, you may also run commands directly as recs-command
,
though this is no longer recommended for forwards compatibility. Both
installation methods provide a top-level recs
executable
which dispatches to commands, so this is the preferred invocation style.
The core recs commands are briefly summarized below, and you can list all
available commands by running recs --list
.
To read more about each command, run recs command --help
. Longer
documentation is available as recs command --help-all
or perldoc recs-command
.
For example, to read more about "fromcsv", you might run any of the
following:
recs fromcsv --help
recs fromcsv --help-all
perldoc recs-fromcsv
-
fromcsv
Produces records from a csv file/stream
-
fromdb
Produces records for a db table, or from a SELECT statement into a db.
-
fromre
Matches input streams against a regex, puts capture groups into hashes
-
frommongo
Generate a record stream from a MongoDB query.
-
frommultire
Matches input streams against several regexes, puts capture groups into the record
-
fromsplit
Splits input stream on a delimiter
-
fromps
Generate records from the process tree
-
fromatomfeed
Produces records for an optionally paginated atom feed.
-
fromxml
Produces records for an XML document.
-
fromkv
Produces records from input streams containing loosely formed key/value pairs
-
fromtcpdump
Produces records from packet capture files (.pcap) as made by tcpdump
-
annotate
Annotate records with common fields, will memoize additions to speed up common annotations
-
collate
Perforce aggregation operations on records. Group by a field, get an average, sum, correlation, etc. Very powerful
-
delta
Transform values into deltas between adjacent records
-
eval
Eval a string of Perl against each record
-
flatten
Flatten records of input to one level
-
grep
Select records for which a string of Perl evaluates to true.
-
multiplex
Take records, grouped by keys, and run a separate recs command for each group.
-
normalizetime
Based on a time field, tag records with a normalized time, i.e. every 5 minute buckets
-
join
Perform an inner join of two record streams. Associate records in one stream with another stream.
-
substream
Filter to a range of matching records with paired Perl snippets
--start
and--end
. -
sort
Sort records based on keys, may specify multiple levels of sorting, as well as numerical or lexical sort ordering
-
topn
Outputs the top n records. You may segment the input based on a list of keys such that unique values of keys are treated as distinct input streams. This enables top n listings per value groupings.
-
xform
Perform a block of Perl on each record, which may modify the record, Record is then output
-
generate
Perform a block of Perl on each record to generate a record stream, which is then output with a chain link back to the original record.
-
todb
Inserts records into a DBI supported SQL database. Will create a local SQLite database by default
-
tocsv
Generates correctly quoted CSV files from record streams.
-
tognuplot
Create a graph of field values in a record using GNU Plot.
-
totable
Pretty prints a table of results.
-
tohtml
Prints out an HTML table of the record stream
-
toprettyprint
Prettily prints records, one key to a line, great for making sense of very large records
-
toptable
Prints a multi-dimensional (pivot) table of values. Very powerful.
Many of the commands above take key arguments to specify or assign to a key in a record. Almost all of the places where you can specify a key (which normally means a first level key in the record), you can instead specify a key spec.
A key spec may be nested, and may index into arrays. Use a /
to nest into a
hash and a #NUM
to index into an array (i.e. #2
)
An example is in order, take a record like this:
{"biz":["a","b","c"],"foo":{"bar 1":1},"zap":"blah1"}
{"biz":["a","b","c"],"foo":{"bar 1":2},"zap":"blah2"}
{"biz":["a","b","c"],"foo":{"bar 1":3},"zap":"blah3"}
In this case a key spec of foo/bar 1
would have the values 1, 2, and 3
respectively.
Similarly, biz/#0
would have the value of a
for all 3 records
You can also prefix key specs with @
to engage the fuzzy matching logic.
Matching is tried like this, in order, with the first key to match winning:
-
- Exact match (
eq
)
- Exact match (
-
- Prefix match (
m/^/
)
- Prefix match (
-
- Match anywhere in the key (
m//
)
- Match anywhere in the key (
Given the above example data and the fuzzy key spec @b/#2
, the b
portion
would expand to biz
and 2
would be the index into the array, so all
records would have the value of c
.
Simiarly, @f/b
would have values 1, 2, and 3.
The data stream format of the recs commands is JSON hashes separated by new lines. If you wish to write your own recs command in your own language, just get a JSON parser and you should be good to go. The recs commands use JSON::MaybeXS.
If you name your command as recs-mycommand
and put it somewhere in your
PATH
environment variable, the recs
command will dispatch to it when
called as recs mycommand
. It will also be included in recs --list
output.
If you want to write your new command in Perl, you can use the same Perl API
that the standard recs toolkit uses. See the various
App::RecordStream::Operation subclasses. Once your new operation class is
installed in perl's library paths, recs
will find it automatically without
the need for any executable command shim.
# look in the custom access log for all accesses with greater than 5 seconds,
# display in a table
cat access.log \
| recs fromre --fields ip,time '^(\d+).*TIME: (\d+)' \
| recs grep '$r->{time} > 5' \
| recs totable
Each of the commands discussed have a --help
mode available to print out
usage and examples for the particular command. See that documentation for
detailed information on the operation of each of the commands. Also see some
other man pages:
- Run
recs examples
or see App::RecordStream::Manual::Examples for a set of simple recs examples - Run
recs story
or see App::RecordStream::Manual::Story for a humorous introduction to RecordStream
Benjamin Bernard perlhacker@benjaminbernard.com
Keith Amling keith.amling@gmail.com
Thomas Sibley tsibley@cpan.org
Copyright 2007–2017 by the AUTHORS
This software is released under the MIT and Artistic 1.0 licenses.