Using vimdiff as a git mergetool can be pretty confusing - multiple windows and little explanation. This is a short tutorial which explains basic usage, and what the LOCAL, BASE, and REMOTE keywords mean. This implies that you have at least a little bit of basic vim knowledge (how to move, save, and switch between split windows). If you don’t, there’s a short article for you: Using vim for writing code. Some basic understanding of git and branching is required as well, obviously.

Git config

Prior to doing anything, you need to know how to set vimdiff as a git mergetool. That being said:

git config merge.tool vimdiff
git config merge.conflictstyle diff3
git config mergetool.prompt false

This will set git as the default merge tool, will display a common ancestor while merging, and will disable the prompt to open the vimdiff.

Creating merge conflict

Let’s create a test situation. You are free to skip this part or you can work along with the tutorial.

mkdir zoo
cd zoo
git init
vi animals.txt

Let’s add some animals:

cat
dog
octopus
octocat

Save the file.

git add animals.txt
git commit -m "Initial commit"
git branch octodog
git checkout octodog
vi animals.txt  # let's change octopus to octodog
git add animals.txt
git commit -m "Replace octopus with an octodog"
git checkout master
vi animals.txt  # let's change octopus to octoman
git add animals.txt
git commit -m "Replace octopus with an octoman"
git merge octodog  # merge octodog into master

That’s where we get a merge error:

Auto-merging animals.txt
CONFLICT (content): Merge conflict in animals.txt
Automatic merge failed; fix conflicts and then commit the result.

Resolving merge conflict with vimdiff

Let’s resolve the conflict:

git mergetool

This looks terrifying at first, but let me explain what is going on.

From left to right, top to the bottom:

LOCAL – this is file from the current branch BASE – common ancestor, how file looked before both changes REMOTE – file you are merging into your branch MERGED – merge result, this is what gets saved in the repo

Let’s assume that we want to keep the “octodog” change (from REMOTE). For that, move to the MERGED file (Ctrl + w, j), move your cursor to a merge conflict area and then:

:diffget RE

This gets the corresponding change from REMOTE and puts it in MERGED file. You can also:

:diffg RE  " get from REMOTE
:diffg BA  " get from BASE
:diffg LO  " get from LOCAL

Save the file and quit (a fast way to write and quit multiple files is :wqa).

Run git commit and you are all set!

This alias has been around the web for quite some time, but it does look fantastic indeed.

To add the alias git pretty-log, execute the following command (join string prior to executing):

git config alias.pretty-log 'log --graph --pretty=format:"%Cred%h%Creset
-%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset"'

I wrote a little script to download gists from the command prompt.

Generate your Github API Token under Settings -> Applications, change it within a script, and then:

chmod +x shgist.py
mv shgist.py ~/bin/shgist

Where ~/bin is a directory in your path. Now you can use it as shgist file to quickly download your gists (Gist on Github).

#!/usr/bin/env python

# Ruslan Osipov <ruslan@rosipov.com>
# Usage: shgist keywords
# Description: Gists downloader

import urllib
import urllib2
import sys
import json

token = 'Personal API Access Token'  # Github Settings -> Applications

class Gist:
    def __init__(self, token):
        """
        token -- str, github token
        """
        self.token = token
        self.url = 'https://api.github.com'

    def find_by_name(self, keywords):
        """
        keywords -- list of strings
        """
        gists, urls = self._get_gists()
        for i, gist in enumerate(gists):
            for keyword in keywords:
                if keyword not in gist:
                    del gists[i]
                    del urls[i]
                    break
        if len(gists) == 0:
            print "Sorry, no gists matching your description"
            return
        if len(gists) == 1:
            self._download_gist(gists[0], urls[0])
            return
        for i, gist in enumerate(gists):
            print i, gist
        while True:
            num = raw_input("Gist number, 'q' to quit: ")
            if num == 'q':
                print "Quiting..."
                return
            try:
                num = int(num)
                if 0 <= num < len(gists):
                    break
                print "Number should be within specified range"
            except:
                print "Only integers or 'q' are allowed"
        self._download_gist(gists[num], urls[num])

    def _download_gist(self, name, url):
        """
        name -- str, filename
        url -- str, raw gist url
        """
        print "Downloading %s..." % name
        gist = self._send_get_request(url)
        open(name, 'wb').write(gist)

    def _get_gists(self):
        """
        Returns 2 lists which should be treated as ordered dict
        """
        url = '/gists'
        response = self._send_get_request(self.url + url)
        response = json.loads(response)
        gists, urls = [], []
        for gist in response:
            for name, meta in gist['files'].items():
                gists.append(name)
                urls.append(meta['raw_url'])
        return gists, urls

    def _send_get_request(self, url):
        """
        url -- str
        """
        headers = {
                'Authorization': 'token ' + self.token
                }
        request = urllib2.Request(url, headers=headers)
        response = urllib2.urlopen(request)
        return response.read()

argv = sys.argv[1:]
if not len(argv):
    print "Usage: shgist keywords"
    sys.exit(0)

gist = Gist(token)
gist.find_by_name(argv)

Shell history can tell a lot about its owner. What’s in your shell?

history | awk '{CMD[$2]++;count++;}
END { for (a in CMD)print CMD[a] " " CMD[a]/count*100 "% " a;}'
| grep -v "./" | column -c3 -s " " -t | sort -nr | nl |  head -n10

     1  580  38.0328%    git         # I keep everything under VCS
     2  202  13.2459%    cd          # Moving around a lot
     3  171  11.2131%    vi          # Favorite text editor
     4  127  8.32787%    ls          # I'm a curious person
     5  43   2.81967%    rm          # I also like when it's clean
     6  26   1.70492%    usrswitch   # https://gist.github.com/ruslanosipov/5453510
     7  25   1.63934%    exit        # I don't like hitting the red cross button
     8  18   1.18033%    source      # Reloading bash configuration files
     9  17   1.11475%    clear       # Like when it's *really* clean
    10  15   0.983607%   gitk        # Sometimes it is too messy for git log

A round-up of The Week Without Colorful Prompt.

I worked with the colors disabled in bash, git, and vim for a week. So how did it go? It is definitely an interesting experience, but such a harsh change that it doesn’t really work out with everything.

Bash

Disabling colorful PS1 and removing color output for ls commands forced me to concentrate more on the actual text, changing the perception of the general bash workflow. I was more concentrated on the task, missed less details, and generally paid more attention to the output.

Git

Never repeat my mistake by disabling colors for git diff. Log and status are fairly easy to read, but the disabling of colors noticeably slows down the workflow.

Vim

Vim without code highlight forces you to remember your code structure more effectively, which is a great thing. Not having a need to rely on color can hint that a programmer has better understanding of the code he/she is writing.

Now that the experiment is over I have mostly returned to using colorful prompt. But I do turn syntax highlight off once in a while - it allows you to see problems from new angle and work more efficiently at finding a solution. Try it and see for yourself!