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gitgithubxargspull-requestgit-alias
hazzik
hazzik

Reputation: 13364

Simplify Xargs expression in git alias

I'm trying to make a git alias to approve pull request(s) on GitHub. The main feature of this alias is ability to octopus merge multiple pull requests.

What I got so far (.gitconfig):

[alias]
    approve = "!f() { git fetch origin $(echo $@ | xargs -n 1 | xargs -I {} echo refs/pull/{}/head:gh-{} ) && git merge $(echo $@ | xargs -n 1 | xargs -I {} echo gh-{}) --edit --log;}; f"

It works as expected, however I want to know if it is possible to simplify arguments processing:

$(echo $@ | xargs -n 1 | xargs -I {} echo refs/pull/{}/head:gh-{} )

and

$(echo $@ | xargs -n 1 | xargs -I {} echo gh-{})

Usage

$ git approve 1 2 3 # to approve pull requests #1, #2 and #3

Output

SHA-1: XXXX

* Merge branches 'gh-1' and 'gh-2'

* gh-1:
  fix 1

* gh-2:
  fix 2

Upvotes: 3

Views: 223

Answers (1)

Ole Tange
Ole Tange

Reputation: 33740

If you have GNU Parallel I think this would work:

approve = "!parallel -X -j1 'git fetch origin refs/pull/{}/head:gh-{} && git merge gh-{} --edit --log' ::: "

All new computers have multiple cores, but most programs are serial in nature and will therefore not use the multiple cores. However, many tasks are extremely parallelizeable:

  • Run the same program on many files
  • Run the same program for every line in a file
  • Run the same program for every block in a file

GNU Parallel is a general parallelizer and makes is easy to run jobs in parallel on the same machine or on multiple machines you have ssh access to.

If you have 32 different jobs you want to run on 4 CPUs, a straight forward way to parallelize is to run 8 jobs on each CPU:

Simple scheduling

GNU Parallel instead spawns a new process when one finishes - keeping the CPUs active and thus saving time:

GNU Parallel scheduling

Installation

A personal installation does not require root access. It can be done in 10 seconds by doing this:

(wget -O - pi.dk/3 || curl pi.dk/3/ || fetch -o - http://pi.dk/3) | bash

For other installation options see http://git.savannah.gnu.org/cgit/parallel.git/tree/README

Learn more

See more examples: http://www.gnu.org/software/parallel/man.html

Watch the intro videos: https://www.youtube.com/playlist?list=PL284C9FF2488BC6D1

Walk through the tutorial: http://www.gnu.org/software/parallel/parallel_tutorial.html

Sign up for the email list to get support: https://lists.gnu.org/mailman/listinfo/parallel

Upvotes: 1

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