HMGit (Haskell Minimal Git)
Haskell Minimal Git (This is not made for practical purposes)
- Focusing on Git version 2.17.1
- This was made for 技術書店11
HMGit has 8 commands: add, cat-file, diff, hash-object, init, ls-files, status, commit
$ stack exec hmgit -- --help
__ ____ __________ __
/ / / / |/ / ____(_) /_
/ /_/ / /|_/ / / __/ / __/
/ __ / / / / /_/ / / /_
/_/ /_/_/ /_/\____/_/\__/
Usage: hmgit [--version] [--db-name <database name>] COMMAND
The subset of awesome content tracker Git
Version: 1.0.0
Commit hash: 76a315cce6bdcfe428338dca5466849eab3868d4
Available options:
-h,--help Show this help text
--version Prints the HMGit suite version that the hmgit program
came from.
--db-name <database name>
hmgit database name
Available commands:
add Add file contents to the index
cat-file Provide content or type and size information for
repository objects
diff Show changes between commits, commit and working
tree, etc
hash-object Compute object ID and optionally creates a blob from
a file
init Create an empty Git repository or reinitialize an
existing one
ls-files Show information about files in the index and the
working tree
status Show the working tree status
commit Record changes to the repositoryEach command can display help.
$ stack exec hmgit -- add --help # e.g. add
Usage: hmgit add [-n|--dry-run] [<pathspec>...]
Add file contents to the index
Available options:
-h,--help Show this help text
-n,--dry-run Don’t actually add the file(s), just show if they
exist and/or will be ignored.
<pathspec>... Files to add content from. see the pathspec entry in
gitglossary(7).The operation from initialization to commit can be reproduced as follows (Currently it is possible to push to a remote repository with the help of git).
$ stack install
$ cd ~/workdir
# init
$ hmgit --db-name .git init test-hmgit && cd test-hmgit
Initialized empty HMGit repository in: test-hmgit
# check status
$ echo hello git > hello
$ hmgit --db-name .git status
New files:
hello
# staging
$ hmgit --db-name .git add hello
$ hmgit --db-name .git status
# commit
$ hmgit --db-name .git commit -m 'hello git commit' --author "roki <roki@example.com>"
[main (commit) ec891bf] hello git commit
# push (git power)
$ git remote add origin git@github.com:falgon/hmgit-playground.git
$ git push origin main
Counting objects: 3, done.
Writing objects: 100% (3/3), 211 bytes | 211.00 KiB/s, done.
Total 3 (delta 0), reused 0 (delta 0)
To github.com:falgon/hmgit-playground.git
+ 41dab4a...ec891bf main -> main
# diff
$ echo meow >> hello
$ hmgit --db-name .git status
Changes files:
hello
$ hmgit --db-name .git diff
--- a/hello
+++ b/hello
@@
hello git
+meow
# cat-file
$ find .git/objects -type f | cut -d/ -f3,4 | sed 's$/$$g' | xargs -n1 hmgit --db-name .git cat-file -t
commit
tree
blob
$ find .git/objects -type f | cut -d/ -f3,4 | sed 's$/$$g' | xargs -n1 hmgit --db-name .git cat-file -s
163
33
10
$ find .git/objects -type f | cut -d/ -f3,4 | sed 's$/$$g' | xargs -n1 hmgit --db-name .git cat-file -p
tree 66eea8c80abea0e9836aab458e48ab9a379186e5
author roki <roki@example.com> 1621539748 +0900
committer roki <roki@example.com> 1621539748 +0900
hello git commit
100644 blob 8d0e41234f24b6da002d962a26c2495ea16a425f hello
hello git
# hash-object
$ echo bow | hmgit --db-name .git hash-object --stdin
de03f25c7324281fc5b6f146fe273fa85b689690
# search recursively with pathspecs (subset)
$ mkdir -p foo/hoge/piyo foo/hoge/bar
$ echo "main = pure ()" > foo/hoge/piyo/a.hs
$ echo "main = pure ()" > foo/hoge/bar/b.hs
$ echo "main = pure ()" > c1.hs
$ hmgit --db-name .git status '*.hs'
New files:
foo/hoge/piyo/a.hs
foo/hoge/bar/b.hs
c1.hs
$ hmgit --db-name .git status '?1.hs'
New files:
c1.hs
# ls-files
$ hmgit --db-name .git add .
$ hmgit --db-name .git ls-files '*.hs'
c1.hs
foo/hoge/bar/b.hs
foo/hoge/piyo/a.hs
$ hmgit --db-name .git ls-files -s '*.hs'
100644 76a9bdb5d48831da2e59c811ecbcbb5a379bdfb5 0 c1.hs
100644 76a9bdb5d48831da2e59c811ecbcbb5a379bdfb5 0 foo/hoge/bar/b.hs
100644 76a9bdb5d48831da2e59c811ecbcbb5a379bdfb5 0 foo/hoge/piyo/a.hs$ stack build$ stack test