NAME
recs-annotate
recs-annotate --help-all
Help from: --help-basic:
Usage: recs-annotate <args> <expr> [<files>]
<expr> is evaluated as perl on each record of input (or records from <files>)
with $r set to a App::RecordStream::Record object and $line set to the
current line number (starting at 1). Records are analyzed for changes, those
changes are applied to each successive record that matches --keys
Only use this script if you have --keys fields that are repeated, otherwise
recs-xform will be faster
IMPORTANT SNIPPET NOTE
Because of the way annotations are recorded, you cannot use UNSHIFT or SPLICE
on array refs that already exist in the record you are modifiying.
Additionally, deletes, removes, unshifts, and other 'removing' operations
will not apply to later records. If you need this behavior, consider using
recs-xform
--e a perl snippet to execute, optional
--E the name of a file to read as a perl snippet
--M module[=...] execute "use module..." before executing
snippet; same behaviour as perl -M
--m module[=...] same as -M, but by default import nothing
--keys Keys to match records by, maybe specified
multiple times, may be a keygroup or keyspec
--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
--help-snippet Help on code snippets
Examples:
# Annotate records with IPs with hostnames, only doing lookup once
... | recs-annotate --key ip '{{hostname}} = `host {{ip}}`'
# Record md5sums of files
... | recs-annotate --key filename '{{md5}} = `md5sum {{filename}}`'
# Add url contents to records
... | recs-annotate --key url '{{contents}} = `curl {{url}}`'
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
Help from: --help-snippet:
CODE SNIPPETS:
Recs code snippets are perl code, with one exception. There a couple of
variables predefined for you, and one piece of special syntax to assist in
modifying hashes.
Special Variables:
$r - the current record object. This may be used exactly like a hash, or you
can use some of the special record functions, see App::RecordStream::Record
for more information
$line - This is the number of records run through the code snippet, starting
at 1. For most scripts this corresponds to the line number of the input to
the script.
$filename - The filename of the originating record. Note: This is only
useful if you're passing filenames directly to the recs script, piping
from other recs scripts or from cat, for instance, will not have a
useful filename.
Special Syntax
Use {{search_string}} to look for a string in the keys of a record, use /
to nest keys. You can nest into arrays by using an index. If you are
vivifying arrays (if the array doesn't exist, prefix your key with # so
that an array rather than a hash will be created to put a / in your key,
escape it twice, i.e. \/
This is exactly the same as a key spec that is always prefaced with a @, see
'man recs' for more info on key specs
For example: A record that looks like:
{ "foo" : { "bar 1" : 1 }, "zoo" : 2}
Could be accessed like this:
# value of zoo # value of $r->{foo}->{bar 1}: (comma separate nested keys)
{{zoo}} {{foo/ar 1}}
# Even assign to values (set the foo key to the value 1)
{{foo}} = 1
# And auto, vivify
{{new_key/array_key/#0}} = 3 # creates an array within a hash within a hash
# Index into an array
{{array_key/#3}} # The value of index 3 of the array ref under the
'array_key' hash key.
This matching is a fuzzy keyspec matching, see --help-keyspecs for
more details.
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.