oh-my-git/levels/low-level/ref-create

43 lines
1.2 KiB
Plaintext

[description]
Let's take a look at "refs" (short for "references")! Refs are not objects, but rather very simple *pointers* to objects! They can help you keep track of what's where.
You can create or update a ref with
git update-ref refs/<refname> <newvalue>
Make sure to always start a ref's name with "refs/"! That's a convention that helps Git find all refs you create. If you forget the "refs/", you will not see the ref.
Create refs that point to all objects in this repository!
[setup]
echo hello > hello
echo world > world
BLOB1=$(git hash-object -w hello)
BLOB2=$(git hash-object -w world)
git add .
TREE=$(git write-tree)
COMMIT=$(git commit-tree $TREE -m "Initial commit")
[setup goal]
echo hello > hello
echo world > world
BLOB1=$(git hash-object -w hello)
BLOB2=$(git hash-object -w world)
git add .
TREE=$(git write-tree)
COMMIT=$(git commit-tree $TREE -m "Initial commit")
git update-ref refs/a $BLOB1
git update-ref refs/b $BLOB2
git update-ref refs/c $TREE
git update-ref refs/d $COMMIT
[win]
OBJECTS=$(git cat-file --batch-check='%(objectname)' --batch-all-objects | sort)
REF_TARGETS=$(git show-ref -s | sort | uniq)
test "$OBJECTS" = "$REF_TARGETS"