NAME
recs-fromre
recs-fromre --help-all
Help from: --help-basic:
Usage: recs-fromre <args> <re> [<files>]
<re> is matched against each line of input (or lines of <files>). Each successfully match results in one output record whose
field values are the capture groups from the match. Lines that do not match are ignored. Keys are named numerically (0, 1, etc.)
or as given by --key.
For spliting on a delimeter, see recs-fromsplit.
Arguments:
--key|-k <key> Comma separated list of key names. May be specified multiple times. may be a key spec, see 'man
recs' for more
--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 greetings
recs-fromre --key name,age '^Hello, my name is (.*) and I am (\d*) years? old$'
Parse a single key named time from a group of digits at the beginning of the line
recs-fromre --key time '^(\d+)'
Map three sets of <>s to a record with keys named 0, 1, and 2
recs-fromre '<(.*)>\s*<(.*)>\s*<(.*)>'
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