Git Tag a Blob Object

前幾天在這篇文章中看到 git 可以 tag blob/tree objects. 紀錄一下要如何 tag 一個 blob object.

Get Blob Object SHA1

• Get blob object’s SHA1 of a tracked file

  git rev-parse COMMIT_ISH:PATH/TO/FILE
  

• Create a new blob object from a non-tracked file

  git hash-object -w PATH/TO/FILE
  

• Create a new blob object from stdin

  cat PATH/TO/FILE | git hash-object -w --stdin
  echo 'blob content' | git hash-object -w --stdin
  

Tag a Blob Object

• Create a tag refers a blob object ```shell

  lightweight

  git tag TAG_NAME BLOB_SHA1

annotated

git tag -a TAG_NAME BLOB_SHA1

# Retrieve Tag Content

* Such a tag cannot be checkout, since it refers to a blob object rather than a commit.
To get the blob content
```shell
git cat-file -p TAG_NAME^{}

Reference

• Git Internals - Git Objects
• Git Internals - Git References
• How to get object ID of a file at a specific commit?