NAME

recs-chain

recs-chain --help-all

Help from: --help-basic:
Usage: recs-chain <command> | <command> | ...
   Creates an in-memory chain of recs operations. This avoid serialization and
   deserialization of records at each step in a complex recs pipeline. For ease
   of use the chain of recs commands main contain non-recs command, anything
   that does not start with a recs- is interpreted as a shell command. That
   command is forked off to the shell. In this case, serialization and
   deserialization costs apply, but only to and from the shell command,
   everything else is done in memory. If you have many shell commands in a row,
   there is extra over head, you should instead consider splitting those into
   separate pipes. See the examples for more information on this.

   Arugments are specified in on the command line separated by pipes. For most
   shells, you will need to escape the pipe character to avoid having the shell
   interpret the pipe as a shell pipe.

   --show-chain                 Before running the commands, print out what will
                                happen in the chain
   --n                          Do not run commands, implies --show-chain
   --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

Examples:
   Parse some fields, sort and collate, all in memory
      recs-chain recs-frommultire 'data,time=(\S+) (\S+)' \| recs-sort --key time=n \| recs-collate --a perc,90,data
   Use shell commands in your recs stream
      recs-chain recs-frommultire 'data,time=(\S+) (\S+)' \| recs-sort --key time=n \| grep foo \| recs-collate --a perc,90,data
   Many shell commands should be split into real pipes
      recs-chain recs-frommultire 'data,time=(\S+) (\S+)' \| recs-xform '$r->{now} = time();' 
        | grep foo | sort | uniq | recs-chain recs-collate --a perc,90,data \| recs-totable

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

RecordStream(3) - Overview of the scripts and the system

recs-examples(3) - A set of simple recs examples

recs-story(3) - A humorous introduction to RecordStream

SCRIPT --help - every script has a --help option, like the output above