Benjamin Bernard > App-RecordStream-3.7.3 > recs-chain

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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
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