rengokantai/pshowgit

pshowgit

#####1 ######2 Git will generate 40-digit hash according content.

echo "content" | git hash-object --stdin

######3

echo "content" | git hash-object --stdin -w  //save in repo .git/objects/
git cat-file 123213143141231213 -t  //show type of the content
git cat-file 123213143141231213 -p  //pretty printing content

######4

git count-objects

#####4 annotated tag is same as commit.(git objects: blobs,trees,commits,annotatedtags)

git cat-file -p tagname    //tag is symbolink of object

#####2 ######1 branchs? is just a reference to a commit. HEAD is refreence to a branch go to .git/refs/heads/master

cat .git/HEAD

checkout =move head + change working area

checkout a commit

git checkout 213213
(Then create several commits)(we must create a new branch to avoid these commits become garbage)
git branch new branch

the head will not be on any branch,just on a commit.(detached head)
#####3

#####4

git show-ref master

a branch is just a reference to a commit.