Lib.rs

countmerge is a fast command-line program (written in Rust) that takes in a tab-separated file that maps keys to counts, and adds up the total count for each key.

It requires the input to be sorted by key, so you should probably run sort on it first.

Essentially, it's uniq that can add.

It takes no options as of now. It just takes in lines on standard input and writes the summed lines to standard output. Lines that don't map a key to an integer count will be output as-is.

Example input:

key A	1
key A	2
key B	3
key C	4
key	C	3
key C	2
key C	1

The output you get is:

key A	3
key B	3
key C	10

Installation

Install Rust 1.14 or later using rustup.

Clone this repository, and run these commands in its directory:

cargo build
cargo install