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=head1 NAME

recs-grep

=head1 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,