NAME
recs-grep
recs-grep --help-all
Help from: --help-basic:
Usage: recs-grep <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 $line set to the
current line number (starting at 1). Records for which the evaluation is a
perl true are printed back out.
Arguments:
--e a perl snippet to execute, optional
--E the name of a file to read as a perl snippet
--M module[=...] execute "use module..." before executing
snippet; same behaviour as perl -M
--m module[=...] same as -M, but by default import nothing
--v Anti-match. Records NOT matching <expr> will
be returned
--C NUM Provide NUM records of context around matches,
equivalent to -A NUM and -B NUM
--A NUM Print out NUM following records after a match
--B NUM Print out the previous NUM records on a match
--filename-key|fk <keyspec> Add a key with the source filename (if no
filename is applicable will put NONE)
Help Options:
--help-all Output all help for this script
--help This help screen
--help-keyspecs Help on keyspecs, a way to index deeply and with regexes
--help-snippet Help on code snippets
Examples:
Filter to records with field 'name' equal to 'John'
recs-grep '$r->{name} eq "John"'
Find fields without ppid = 3456
recs-grep -v '{{ppid}} == 3456'
Filter to records with all methods equal to 'PUT'
recs-grep -MList::MoreUtils=all 'all { $_ eq 'PUT' } @{$r->{methods}}'
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.