#!/usr/bin/env bash

#

# @license Apache-2.0

#

# Copyright (c) 2017 The Stdlib Authors.

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

# http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

# Prints author commit intervals (in seconds).

#

# <interval> <author_first_name> <author_last_name>

#

# References:

#

# - Kolassa, Carsten, Dirk Riehle, and Michel A. Salim. 2013. "The Empirical Commit Frequency Distribution of Open Source Projects." In _Proceedings of the 9th International Symposium on Open Collaboration_, 18:1–:8. WikiSym '13. New York, NY, USA: ACM. doi:[10.1145/2491055.2491073](http://dx.doi.org/10.1145/2491055.2491073).

# * `git log`

# - Show the commit timestamp and author for each commit.

# * `sort -n`

# - Sort in numeric order.

# * `awk '{}'`

# - Compute the interval since the last commit,

git log --format=format:"%at %aN" --reverse | sort -n | awk '

{

ts = $1

first = $2

if (NF == 2) {

last = "(null)"

} else {

last = $3

}

key = first OFS last

if (key in prev) {

print (ts - prev[key]) OFS key

prev[key] = ts

} else {

prev[key] = ts

}

}

'