NAME
recs-delta
recs-delta --help-all
Help from: --help-basic:
Usage: recs-delta <args> [<files>]
Transforms absolute values into deltas between adjacent records.
Arguments:
--key|-k <keys> Comma separated list of the fields that should
be transformed. Fields not in this list will be
passed through unchanged, using the *first*
record of each delta pair. This may be a keyspec
or a keygroup, see "--help-keyspecs" for more
information
--filename-key|fk <keyspec> Add a key with the source filename (if no
filename is applicable will put NONE)
Help Options:
--help-all Output all help for this script
--help This help screen
--help-keygroups Help on keygroups, a way of specifying multiple keys
--help-keys Help on keygroups and keyspecs
--help-keyspecs Help on keyspecs, a way to index deeply and with regexes
Examples:
Transforms a cumulative counter of errors into a count of errors per record.
recs-delta --key=errors
Help from: --help-keygroups:
KEY GROUPS
SYNTAX: !regex!opt1!opt2... Key groups are a way of specifying multiple
fields to a recs command with a single argument or function. They are
generally regexes, and have several options to control what fields they
match. By default you give a regex, and it will be matched against all first
level keys of a record to come up with the record list. For instance, in a
record like this:
{ 'zip': 1, 'zap': 2, 'foo': { 'bar': 3 } }
Key group: !z! would get the keys 'zip' and 'zap'
You can have a literal '!' in your regex, just escape it with a \.
Normally, key groups will only match keys whose values are scalars. This can
be changed with the 'returnrefs' or rr flag.
With the above record !f! would match no fields, but !f!rr would match foo
(which has a value of a hash ref)
Options on KeyGroups:
returnrefs, rr - Return keys that have reference values (default:off)
full, f - Regex should match against full keys (recurse fully)
depth=NUM,d=NUM - Only match keys at NUM depth (regex will match against
full keyspec)
sort, s - sort keyspecs lexically
Help from: --help-keyspecs:
KEY SPECS
A key spec is short way of specifying a field with prefixes or regular
expressions, it may also be nested into hashes and 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 in
the respective records.
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
Fuzzy matching works like this in order, first key to match wins
1. Exact match ( eq )
2. Prefix match ( m/^/ )
3. Match anywehre in the key (m//)
So, in the above example '@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
You can escape / with a \. For example, if you have a record:
{"foo/bar":2}
You can address that key with foo\/bar
SEE ALSO
See App::RecordStream for an overview of the scripts and the system
Run
recs examples
or see App::RecordStream::Manual::Examples for a set of simple recs examplesRun
recs story
or see App::RecordStream::Manual::Story for a humorous introduction to RecordStreamEvery command has a
--help
mode available to print out usage and examples for the particular command, just like the output above.