Write Yourself a Git on Everyone Has a Story

Another Attempt at Wag3

BhaveshSGupta@disroot.org (Bhavesh S. Gupta) — Sun, 25 Aug 2019 16:57:46 +0530

Until now we had done as of following code. We would create couples of more functions which would help us in managing our application. As discussed earlier we would now we creating different directories and files present inside .git directory along with directory itself. More or less we would something like following directory structure after doing wag init

.git is the git directory itself, which contains:
- .git/objects/ : the object store, which we’ll introduce in the next section.
- .git/refs/ the reference store, which we’ll discuss . It contains two subdirectories, heads and tags.
- .git/HEAD, a reference to the current HEAD (more on that later!)
- .git/config, the repository’s configuration file.
- .git/description, the repository’s description file.

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import sys
import argparse
import os

argparser = argparse.ArgumentParser(description="Another Content Tracker")
argsubparsers = argparser.add_subparsers(title="Commands", dest="command")
argsubparsers.required = True
argsp = argsubparsers.add_parser(
 "init", help="Initialize a new, empty repository.")
argsp.add_argument("path", metavar="directory", nargs="?",
 default=".", help="Where to create the repository.")


def main(argv=sys.argv[1:]):
 args = argparser.parse_args(argv)
 if args.command == "init":
 cmd_init(args)


def cmd_init(args):
 repo_create(args.path)


class GitRepository(object):
 """A git repository"""
 worktree = None
 gitdir = None

 def __init__(self, path, force=False):
 self.worktree = path
 self.gitdir = os.path.join(path, ".git")


def repo_create(path):
 """Create a new repository at path."""
 repo = GitRepository(path)
 # We check whether there exsits a path of worktree
 if os.path.exists(repo.worktree):
 # if path exsits its a directory or not
 if not os.path.isdir(repo.worktree):
 raise Exception("%s is not a directory!" % path)
 # if path exsits its empty or not
 if os.listdir(repo.worktree):
 raise Exception("%s is not empty!" % path)
 else:
 # Create directory as nothing exist with same path
 os.makedirs(repo.worktree)

Now let’s create function which would gives us path of directory after verifying that the directory exist and if it doesn’t it should gives us an error. We would also require mechanism to check whether we need to create the directory or not if it doesn’t exists.

Another Attempt at Wag 2

BhaveshSGupta@disroot.org (Bhavesh S. Gupta) — Sat, 24 Aug 2019 15:32:32 +0530

Last time we had created cmd_init(args) function. We add more functionality to cmd_init(args).

This was our code till last time.

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import sys
import argparse

argparser = argparse.ArgumentParser(description="Another Content Tracker")
argsubparsers = argparser.add_subparsers(title="Commands", dest="command")
argsubparsers.required = True
argsp = argsubparsers.add_parser("init", help="Initialize a new, empty repository.")
argsp.add_argument("path", metavar="directory", nargs="?", default=".", help="Where to create the repository.")

def main(argv=sys.argv[1:]):
 args = argparser.parse_args(argv)
 if args.command == "init":
 cmd_init(args)
 

def cmd_init(args):
 print("Hello from init")
 

We had added an argument to your sub parser called path. If the value of path is not specified it would be ‘.’ current directory or it would whatever specified. This would help us

Another Attempt to write a git

BhaveshSGupta@disroot.org (Bhavesh S. Gupta) — Thu, 22 Aug 2019 20:50:56 +0530

Second Try

We would be trying to create a mini git clone from this tutorial. I aspect this to go long. In general git is awesome source code manager which is wieldy use.

So first we would be creating a lib file and executing file.

Let’s create a file called wag which would have following code.

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#!/usr/bin/env python3

import libwag
libwag.main()

Then we would create another file which would be libwag.py with just a main function in it.

An attempt to Write Yourself a Git

BhaveshSGupta@disroot.org (Bhavesh S. Gupta) — Mon, 19 Aug 2019 21:13:07 +0530

So I tried to follow wyag at here but I was not able to. This tutorial is great but I was not able follow it because may be I am not still not much clear with python and how it works. So after much thought I have decided that I would try to create my own blog post series where I would take learnings from wyag and try to do it in my way.