Rjoin

rjoin is a new command line utility for joining records of two files on common fields.

Dual-licensed under MIT or unlicense

Documentation

Installation

The binary name for rjoin is rj.

bash $ cargo --version cargo 0.25.0-nightly (a88fbace4 2017-12-29) # requires nightly channel $ RUSTFLAGS="-C target-cpu=native" cargo install rjoin

(don't forget to add $HOME/.cargo/bin to your path).

Why should you use `rjoin`?

it can perform the join on multiple fields
it has higher flexibilty on specifying the field separators and record terminators compared to GNU join
it has (subjectively) cleaner CLI.

Why you should not use `rjoin`?

you need a specific output format. GNU join is more flexible on this, but it can be mitigated by piping the output to awk.
you need a case insensitive join. This can be mitigated by preprocessing data with tr utility.
you don't have an AVX2 capable CPU.

Quick Example

Let's suppose we have the following data:

```bash $ cat left color,blue color,green color,red shape,circle shape,square

$ cat right altitude,low
altitude,high
color,orange
color,purple
``` To get the lines with the common key:

bash $ rj left right color,blue,orange color,blue,purple color,green,orange color,green,purple color,red,orange color,red,purple

Some comments:

by default, the first field is the key. If you wish to use another field, you can specify it using --key/-k option (even per file). rj supports multiple fields as the key, but the number of key fields in both files must be equal.
by default, only the lines with the common key are printed. If you wish to print also unmached lines from the left or right file, use any combination of these: --show-left/-l, --show-right/-r or --show-both/-b. Note however, if you use any of these options, the default behavior is reset (e.g. if you want to see the unmatched lines in the left file along with the matched lines, use -lb. With -l you will not see the matched lines.)
there are multiple lines with the same key in both files, resulting in Cartesian product.

To get the lines with the unmatched key in both files:

bash $ rj -lr left right altitude,low altitude,high shape,circle shape,square

Check the tutorial for the detailed walkthrough.

Contributing

Any kind of contribution (e.g. comment, suggestion, question, bug report and pull request) is welcome.

Why Rust?

Because C eats a bloody lot of mental resources only to avoid shooting my leg, or worse.

Acknowledgments

The CSV parser used in Rjoin is based on the work of Y. Li, N. R. Katsipoulakis, B. Chandramouli, J. Goldstein, and D. Kossmann. Mison: a fast JSON parser for data analytics. In VLDB, 2017.

The SIMD part was shamelessly copied from pikkr

And finally a big thanks to BurntSushi for his excellent work.