Convert "internal" levels to new level format

This commit is contained in:
Sebastian Morr 2020-10-12 18:54:27 +02:00
parent 613b1b9852
commit 53a6885ef9
108 changed files with 727 additions and 382 deletions

26
levels/internals/basics Normal file
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[description]
For this prototype, we assume you have some experience with the command line. Here are some commands that will be useful:
- ls
- echo content > file
- cat file
- mkdir dir
Find the riddle in your current directory and put the answer into the file "answer"!
[congrats]
Omnomnom!
For technical reasons, you can't use `cd` in this prototype yet. But there won't be a lot of interaction with the file system anyways. :)
[setup]
mkdir riddle
echo "ppl p" > riddle/consonants
echo "ae ie" > riddle/vowels
[win]
cat answer | grep -i "apple \\?pie"

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Omnomnom!
For technical reasons, you can't use `cd` in this prototype yet. But there won't be a lot of interaction with the file system anyways. :)

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For this prototype, we assume you have some experience with the command line. Here are some commands that will be useful:
- ls
- echo content > file
- cat file
- mkdir dir
Find the riddle in your current directory and put the answer into the file "answer"!

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mkdir riddle
echo "ppl p" > riddle/consonants
echo "ae ie" > riddle/vowels

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cat answer | grep -i "apple \\?pie"

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[description]
At its core, Git is very simple. It stores "objects", which are basically files identified by an "identifier" (short: ID).
There are four types of objects: blobs, trees, commits, and tags. The simplest type is a "blob", which is just a piece of text.
Let's create some blobs! To do that, create a file with the desired content, and then use
git hash-object -w <file>
The flag -w means "write", and tells Git to actually write the new blob to the disk.
Create three new blobs!
[congrats]
Tip: You can also use a command like this to create a blob in a single line:
echo "awesome content" | git hash-object -w --stdin
Did you already notice that you can drag and drop all objects? :)
[setup]
[setup goal]
echo "Hi" > file1
echo "Ho" > file2
echo "Hu" > file3
git hash-object -w file1
git hash-object -w file2
git hash-object -w file3
[win]
BLOB_COUNT=$(git cat-file --batch-check='%(objectname) %(objecttype)' --batch-all-objects | grep blob | wc -l)
test "$BLOB_COUNT" -gt 2

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Tip: You can also use a command like this to create a blob in a single line:
echo "awesome content" | git hash-object -w --stdin
Did you already notice that you can drag and drop all objects? :)

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At its core, Git is very simple. It stores "objects", which are basically files identified by an "identifier" (short: ID).
There are four types of objects: blobs, trees, commits, and tags. The simplest type is a "blob", which is just a piece of text.
Let's create some blobs! To do that, create a file with the desired content, and then use
git hash-object -w <file>
The flag -w means "write", and tells Git to actually write the new blob to the disk.
Create three new blobs!

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echo "Hi" > file1
echo "Ho" > file2
echo "Hu" > file3
git hash-object -w file1
git hash-object -w file2
git hash-object -w file3

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BLOB_COUNT=$(git cat-file --batch-check='%(objectname) %(objecttype)' --batch-all-objects | grep blob | wc -l)
test "$BLOB_COUNT" -gt 2

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[description]
There's a simple command to remove all objects that are not referenced by anything:
git prune
Remove all blobs in this repository.
[congrats]
Generally, `git prune` will be useful if you want to clean up some objects you made.
Alternatively, you can also click the "Reload" button to restart a level.
[setup]
echo "My master password is a1b2c3d4e5" | git hash-object -w --stdin
echo "This blob really should not exist" | git hash-object -w --stdin
echo "This is a virus" | git hash-object -w --stdin
[setup goal]
[win]
OBJECT_COUNT=$(git cat-file --batch-check='%(objectname) %(objecttype)' --batch-all-objects | wc -l)
test "$OBJECT_COUNT" -eq 0

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Generally, `git prune` will be useful if you want to clean up some objects you made.
Alternatively, you can also click the "Reload" button to restart a level.

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There's a simple command to remove all objects that are not referenced by anything:
git prune
Remove all blobs in this repository.

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git prune

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echo "My master password is a1b2c3d4e5" | git hash-object -w --stdin
echo "This blob really should not exist" | git hash-object -w --stdin
echo "This is a virus" | git hash-object -w --stdin

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OBJECT_COUNT=$(git cat-file --batch-check='%(objectname) %(objecttype)' --batch-all-objects | wc -l)
test "$OBJECT_COUNT" -eq 0

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[description]
So a tree describes a directory structure at a specific point in time.
It would be nice if we could remember when that state existed, and who authored it, right?
Enter: commits. They are objects that point to a tree and contain some additional metadata. You can create a commit using
git commit-tree <tree> -m "Description of your commit"
Make a commit from the tree in this repository!
[setup]
touch empty_file
git add .
git write-tree
rm empty_file
git update-index --remove empty_file
[setup goal]
touch empty_file
git add .
git write-tree
rm empty_file
git update-index --remove empty_file
git commit-tree 3185 -m 'Clever commit message'
[win]
COMMIT_COUNT=$(git cat-file --batch-check='%(objectname) %(objecttype)' --batch-all-objects | grep commit | wc -l)
test "$COMMIT_COUNT" -gt 0

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So a tree describes a directory structure at a specific point in time.
It would be nice if we could remember when that state existed, and who authored it, right?
Enter: commits. They are objects that point to a tree and contain some additional metadata. You can create a commit using
git commit-tree <tree> -m "Description of your commit"
Make a commit from the tree in this repository!

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git commit-tree 3185 -m 'Clever commit message'

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touch empty_file
git add .
git write-tree
rm empty_file
git update-index --remove empty_file

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COMMIT_COUNT=$(git cat-file --batch-check='%(objectname) %(objecttype)' --batch-all-objects | grep commit | wc -l)
test "$COMMIT_COUNT" -gt 0

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[description]
When using the commit-tree command, you can optionally specify a parent:
git commit-tree <tree> -m "Description" -p <parent commit>
Make a string of three commits!
Hint: You'll need a tree object. What could be the easiest way to obtain one?
[setup]
[setup goal]
git write-tree
FIRST_COMMIT=$(git commit-tree 4b82 -m 'First commit :O')
SECOND_COMMIT=$(git commit-tree 4b82 -p $FIRST_COMMIT -m 'Second commit :D')
THIRD_COMMIT=$(git commit-tree 4b82 -p $SECOND_COMMIT -m 'Third commit \o/')
[win]
COMMITS=$(git cat-file --batch-check='%(objectname) %(objecttype)' --batch-all-objects | grep commit | cut -f1 -d" ")
for COMMIT in $COMMITS; do
echo a commit named $COMMIT
if [ $(git rev-list $COMMIT | wc -l) -ge 3 ]; then
return 0
fi
done
return 1

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When using the commit-tree command, you can optionally specify a parent:
git commit-tree <tree> -m "Description" -p <parent commit>
Make a string of three commits!
Hint: You'll need a tree object. What could be the easiest way to obtain one?

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git write-tree
FIRST_COMMIT=$(git commit-tree 4b82 -m 'First commit :O')
SECOND_COMMIT=$(git commit-tree 4b82 -p $FIRST_COMMIT -m 'Second commit :D')
THIRD_COMMIT=$(git commit-tree 4b82 -p $SECOND_COMMIT -m 'Third commit \o/')

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COMMITS=$(git cat-file --batch-check='%(objectname) %(objecttype)' --batch-all-objects | grep commit | cut -f1 -d" ")
for COMMIT in $COMMITS; do
echo a commit named $COMMIT
if [ $(git rev-list $COMMIT | wc -l) -ge 3 ]; then
return 0
fi
done
return 1

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[description]
A commit can have multiple parents! You can specify the -p option multiple times, like this:
git commit-tree <tree> -m "Description" -p <parent1> -p <parent2>
Build a rhombus shape from commits, where two commits point to the same parent, and then a fourth commit points to both of them.
[setup]
[setup goal]
TREE=$(git write-tree)
SOUTH=$(git commit-tree $TREE -m "South")
EAST=$(git commit-tree $TREE -m "East" -p $SOUTH)
WEST=$(git commit-tree $TREE -m "West" -p $SOUTH)
NORTH=$(git commit-tree $TREE -m "Nort" -p $EAST -p $WEST)
[win]
COMMITS=$(git cat-file --batch-check='%(objectname) %(objecttype)' --batch-all-objects | grep commit | cut -f1 -d" ")
for COMMIT in $COMMITS; do
# My first parent's parents has to be the same as my second parent's parent.
if [ "$(git rev-parse --verify -q $COMMIT^1^)" = "$(git rev-parse --verify -q $COMMIT^2^)" ]; then
return 0
fi
done
return 1

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A commit can have multiple parents! You can specify the -p option multiple times, like this:
git commit-tree <tree> -m "Description" -p <parent1> -p <parent2>
Build a rhombus shape from commits, where two commits point to the same parent, and then a fourth commit points to both of them.

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TREE=$(git write-tree)
SOUTH=$(git commit-tree $TREE -m "South")
EAST=$(git commit-tree $TREE -m "East" -p $SOUTH)
WEST=$(git commit-tree $TREE -m "West" -p $SOUTH)
NORTH=$(git commit-tree $TREE -m "Nort" -p $EAST -p $WEST)

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COMMITS=$(git cat-file --batch-check='%(objectname) %(objecttype)' --batch-all-objects | grep commit | cut -f1 -d" ")
for COMMIT in $COMMITS; do
# My first parent's parents has to be the same as my second parent's parent.
if [ "$(git rev-parse --verify -q $COMMIT^1^)" = "$(git rev-parse --verify -q $COMMIT^2^)" ]; then
return 0
fi
done
return 1

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[description]
(This is not a real puzzle yet.)
Try merging the two branches together!
git merge <otherbranch>
[setup]
echo ? > bikeshed_color
git add .
git commit -m "Initial commit"
echo green > bikeshed_color
git commit -a -m "My suggestion"
git switch -c alternative HEAD^
echo blue > bikeshed_color
git commit -a -m "This is way better"
git switch main
[setup goal]
echo ? > bikeshed_color
git add .
git commit -m "Initial commit"
echo green > bikeshed_color
git commit -a -m "My suggestion"
git switch -c alternative HEAD^
echo blue > bikeshed_color
git commit -a -m "This is way better"
git switch main
git merge alternative
echo blue-green > bikeshed_color
git add .
git commit -m "Merge"
git prune

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(This is not a real puzzle yet.)
Try merging the two branches together!
git merge <otherbranch>

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git merge alternative
echo blue-green > bikeshed_color
git add .
git commit -m "Merge"
git prune

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echo ? > bikeshed_color
git add .
git commit -m "Initial commit"
echo green > bikeshed_color
git commit -a -m "My suggestion"
git switch -c alternative HEAD^
echo blue > bikeshed_color
git commit -a -m "This is way better"
git switch main

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[description]
Blobs usually represent the content of a file. But on their own, they don't have any metadata, not even a name!
Git has a very powerful concept to store metadata related to blobs: the index! It's a list that relates blobs to filenames and access permissions.
The most convenient option to add an entry to the index is via an existing file:
echo "my content" > file
git update-index --add file
Add three entries to the index! For a bonus challenge: can you add a file that is inside of a directory, like "directory/file"?
[congrats]
There's another way to add an entry to the index directly:
git update-index --add --cacheinfo <mode>,<blobhash>,<name>
The first three numbers of the mode describe the type of the entry, "100" is a regular file.
The second three number describe the permissions. Only "644" (non-executable) and "755" (executable) are supported.
You can insert the hash of an object into the terminal by right-clicking on it! :)
[setup]
[setup goal]
echo "file 1" > file1
echo "file 2" > file2
echo "file 3" > file3
git add .
[win]
test "$(git ls-files | wc -l)" -ge 3

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There's another way to add an entry to the index directly:
git update-index --add --cacheinfo <mode>,<blobhash>,<name>
The first three numbers of the mode describe the type of the entry, "100" is a regular file.
The second three number describe the permissions. Only "644" (non-executable) and "755" (executable) are supported.
You can insert the hash of an object into the terminal by right-clicking on it! :)

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@ -1,10 +0,0 @@
Blobs usually represent the content of a file. But on their own, they don't have any metadata, not even a name!
Git has a very powerful concept to store metadata related to blobs: the index! It's a list that relates blobs to filenames and access permissions.
The most convenient option to add an entry to the index is via an existing file:
echo "my content" > file
git update-index --add file
Add three entries to the index! For a bonus challenge: can you add a file that is inside of a directory, like "directory/file"?

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echo "file 1" > file1
echo "file 2" > file2
echo "file 3" > file3
git add .

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test "$(git ls-files | wc -l)" -ge 3

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[description]
To remove an entry from the index, use a command like this:
git update-index --force-remove <file>
Remove all entries from the index!
[setup]
echo "file 1" > file1
echo "file 2" > file2
echo "file 3" > file3
git add .
[setup goal]
echo "file 1" > file1
echo "file 2" > file2
echo "file 3" > file3
git add .
git update-index --force-remove file1
git update-index --force-remove file2
git update-index --force-remove file3
[win]
test "$(git ls-files | wc -l)" -eq 0

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To remove an entry from the index, use a command like this:
git update-index --force-remove <file>
Remove all entries from the index!

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git update-index --force-remove file1
git update-index --force-remove file2
git update-index --force-remove file3

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echo "file 1" > file1
echo "file 2" > file2
echo "file 3" > file3
git add .

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test "$(git ls-files | wc -l)" -eq 0

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[description]
Instead of removing an entry from the index and adding one with the same name, you can also directly update that entry!
Put the content you want in a file with a matching name, and then run
git update-index <file>
This will create a new blob, and update the hash of the entry to that blob.
Update an entry in the index!
[setup]
echo "file 1" > file1
echo "file 2" > file2
echo "file 3" > file3
git add .
[setup goal]
echo "file 1" > file1
echo "file 2" > file2
echo "file 3" > file3
git add .
echo "new content" > file1
git update-index file1
[win]
# This is not really a good test for the winning condition...
test "$(git ls-files -s | git hash-object --stdin)" != "10c4b28623e7e44e09f5a596450a50ab7ac31fbe" -a "$(git ls-files | wc -l)" -eq 3

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Instead of removing an entry from the index and adding one with the same name, you can also directly update that entry!
Put the content you want in a file with a matching name, and then run
git update-index <file>
This will create a new blob, and update the hash of the entry to that blob.
Update an entry in the index!

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echo "new content" > file1
git update-index file1

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echo "file 1" > file1
echo "file 2" > file2
echo "file 3" > file3
git add .

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# This is not really a good test for the winning condition...
test "$(git ls-files -s | git hash-object --stdin)" != "10c4b28623e7e44e09f5a596450a50ab7ac31fbe" -a "$(git ls-files | wc -l)" -eq 3

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[description]
Delete all objects in this repository using git commands only!
Useful commands:
git prune
git fsck
git reflog expire
Note: I'm not sure how to beat this level. :D
[setup]
echo foo > foo
BLOB=$(git hash-object -w foo)
echo bar > bar
git add .
git commit -m "Initial commit"
echo blabber >> bar
git commit -a -m "Second commit"
git update-ref refs/important HEAD
git update-ref refs/interesting "$BLOB"
[setup goal]
echo foo > foo
BLOB=$(git hash-object -w foo)
echo bar > bar
git add .
git commit -m "Initial commit"
echo blabber >> bar
git commit -a -m "Second commit"
git update-ref refs/important HEAD
git update-ref refs/interesting "$BLOB"
TREE=$(git mktree)
git read-tree $TREE
rm -rf .git/refs/*
rm -rf .git/objects/*
[win]
test "$(git cat-file --batch-check --batch-all-objects | wc -l)" -eq 0

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Delete all objects in this repository using git commands only!
Useful commands:
git prune
git fsck
git reflog expire
Note: I'm not sure how to beat this level. :D

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TREE=$(git mktree)
git read-tree $TREE
rm -rf .git/refs/*
rm -rf .git/objects/*

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echo foo > foo
BLOB=$(git hash-object -w foo)
echo bar > bar
git add .
git commit -m "Initial commit"
echo blabber >> bar
git commit -a -m "Second commit"
git update-ref refs/important HEAD
git update-ref refs/interesting "$BLOB"

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@ -1 +0,0 @@
test "$(git cat-file --batch-check --batch-all-objects | wc -l)" -eq 0

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[description]
Create two trees pointing to the same blob!
[setup]
[setup goal]
BLOB=$(echo "I am precious" | git hash-object -w --stdin)
git update-index --add --cacheinfo 100644,$BLOB,a
git write-tree
git update-index --force-remove a
git update-index --add --cacheinfo 100644,$BLOB,b
git write-tree
git update-index --force-remove b
[win]
TREES=$(git cat-file --batch-check='%(objectname) %(objecttype)' --batch-all-objects | grep tree | cut -f1 -d" ")
ALL_TREE_CHILDREN=$(for TREE in $TREES; do

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Create two trees pointing to the same blob!

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BLOB=$(echo "I am precious" | git hash-object -w --stdin)
git update-index --add --cacheinfo 100644,$BLOB,a
git write-tree
git update-index --force-remove a
git update-index --add --cacheinfo 100644,$BLOB,b
git write-tree
git update-index --force-remove b

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[description]
Construct a chain of three trees, which don't point to anything else.
This is hard! The `git mktree` command might be useful.
[setup]
[setup goal]
git mktree
TREE=$(echo -e "040000 tree 4b825dc642cb6eb9a060e54bf8d69288fbee4904\tdir" | git mktree)
echo -e "040000 tree $TREE\tdir" | git mktree
[win]
TREES=$(git cat-file --batch-check='%(objectname) %(objecttype)' --batch-all-objects | grep tree | cut -f1 -d" ")
for TREE in $TREES; do

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Construct a chain of three trees, which don't point to anything else.
This is hard! The `git mktree` command might be useful.

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git mktree
TREE=$(echo -e "040000 tree 4b825dc642cb6eb9a060e54bf8d69288fbee4904\tdir" | git mktree)
echo -e "040000 tree $TREE\tdir" | git mktree

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[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"

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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!

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git update-ref refs/a $BLOB1
git update-ref refs/b $BLOB2
git update-ref refs/c $TREE
git update-ref refs/d $COMMIT

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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")

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OBJECTS=$(git cat-file --batch-check='%(objectname)' --batch-all-objects | sort)
REF_TARGETS=$(git show-ref -s | sort | uniq)
test "$OBJECTS" = "$REF_TARGETS"

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[description]
You can point refs to a new location using the same command you use to create them:
git update-ref refs/<refname> <object>
As an exercise, make all refs in this repository point to the tree object!
[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 $TREE -m "Initial commit")
git update-ref refs/a "$BLOB1"
git update-ref refs/b "$COMMIT"
[setup goal]
echo hello > hello
echo world > world
BLOB1=$(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 "$COMMIT"
for REF in $(git for-each-ref --format='%(refname)'); do
git update-ref "$REF" "$TREE"
done
[win]
test "$(git show-ref -s | sort -u)" = "c7863f72467ed8dd44f4b8ffdb8b57ca7d91dc9e"

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You can point refs to a new location using the same command you use to create them:
git update-ref refs/<refname> <object>
As an exercise, make all refs in this repository point to the tree object!

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@ -1,3 +0,0 @@
for REF in $(git for-each-ref --format='%(refname)'); do
git update-ref "$REF" "$TREE"
done

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@ -1,10 +0,0 @@
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 "$COMMIT"

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@ -1 +0,0 @@
test "$(git show-ref -s | sort -u)" = "c7863f72467ed8dd44f4b8ffdb8b57ca7d91dc9e"

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@ -0,0 +1,41 @@
[description]
And finally, to delete a ref, use
git update-ref -d refs/<refname>
Delete all refs! :P (Well, except for HEAD. HEAD is special.)
[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 $TREE -m "Initial commit")
git update-ref refs/best_blob_ever "$BLOB1"
git update-ref refs/beautiful_commit "$COMMIT"
[setup goal]
echo hello > hello
echo world > world
BLOB1=$(git hash-object -w hello)
BLOB2=$(git hash-object -w world)
git add .
TREE=$(git write-tree)
COMMIT=$(git commit-tree $TREE -m "Initial commit")
git update-ref refs/best_blob_ever "$BLOB1"
git update-ref refs/beautiful_commit "$COMMIT"
for REF in $(git for-each-ref --format='%(refname)'); do
git update-ref -d "$REF"
done
[win]
test "$(git show-ref | wc -l)" -eq 0

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@ -1,5 +0,0 @@
And finally, to delete a ref, use
git update-ref -d refs/<refname>
Delete all refs! :P (Well, except for HEAD. HEAD is special.)

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@ -1,3 +0,0 @@
for REF in $(git for-each-ref --format='%(refname)'); do
git update-ref -d "$REF"
done

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@ -1,10 +0,0 @@
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 $TREE -m "Initial commit")
git update-ref refs/best_blob_ever "$BLOB1"
git update-ref refs/beautiful_commit "$COMMIT"

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@ -1 +0,0 @@
test "$(git show-ref | wc -l)" -eq 0

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@ -1,3 +1,5 @@
[description]
Instead of pointing directly to objects, refs can also point to other refs!
When that happens, they are called "symbolic refs". You can create or update a symbolic ref using
@ -5,3 +7,15 @@ When that happens, they are called "symbolic refs". You can create or update a s
git symbolic-ref <name> <ref>
Create a symbolic ref called "refs/rainbow"!
[setup]
[setup goal]
BLOB=$(git hash-object -w --stdin)
git update-ref refs/double "$BLOB"
git symbolic-ref refs/rainbow refs/double
[win]
git symbolic-ref refs/rainbow

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@ -1,3 +0,0 @@
BLOB=$(git hash-object -w --stdin)
git update-ref refs/double "$BLOB"
git symbolic-ref refs/rainbow refs/double

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@ -1 +0,0 @@
git symbolic-ref refs/rainbow

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@ -0,0 +1,46 @@
[description]
When you have a symbolic ref (a ref pointing at another ref), and you decide you want it to be a regular ref again (pointing to an object), you're in for some trouble! :)
What happens when you try pointing the symbolic ref directly to the blob using `git update-ref`?
Oops! Turns out that when you reference a symbolic ref, it acts as if you had specified the ref it points to. To de-symbolic-ize it, use the `--no-deref` option directly after `update-ref`!
Weird, huh?
[congrats]
Whew, we've covered a lot of things: Blobs! The index! Trees! Commits! Refs!
You now know about almost everything about how Git repositories look like on the inside! We think that's pretty cool! :)
Everything else is just convention and high-level commands that make interacting with the objects more convenient.
We haven't covered:
- tag objects (they are the fourth object type - a bit like refs with a description and an author)
- configuration (allows you to specify remote repositories, for example)
- working with local files (which is, uh, arguably pretty important :P)
Thanks for playing! You're welcome to check out the "puzzle" levels in the dropdown, some of them are more advanced!
[setup]
BLOB1=$(echo delicious | git hash-object -w --stdin)
BLOB2=$(echo very | git hash-object -w --stdin)
git update-ref refs/curly "$BLOB1"
git symbolic-ref refs/fries refs/curly
[setup goal]
BLOB1=$(echo delicious | git hash-object -w --stdin)
BLOB2=$(echo very | git hash-object -w --stdin)
git update-ref refs/curly "$BLOB1"
git symbolic-ref refs/fries refs/curly
git update-ref --no-deref refs/fries "$BLOB2"
[win]
git symbolic-ref refs/fries && return 1
test "$(git show-ref -s refs/fries)" = "035e2968dafeea08e46e8fe6743cb8123e8b9aa6"

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@ -1,13 +0,0 @@
Whew, we've covered a lot of things: Blobs! The index! Trees! Commits! Refs!
You now know about almost everything about how Git repositories look like on the inside! We think that's pretty cool! :)
Everything else is just convention and high-level commands that make interacting with the objects more convenient.
We haven't covered:
- tag objects (they are the fourth object type - a bit like refs with a description and an author)
- configuration (allows you to specify remote repositories, for example)
- working with local files (which is, uh, arguably pretty important :P)
Thanks for playing! You're welcome to check out the "puzzle" levels in the dropdown, some of them are more advanced!

View file

@ -1,7 +0,0 @@
When you have a symbolic ref (a ref pointing at another ref), and you decide you want it to be a regular ref again (pointing to an object), you're in for some trouble! :)
What happens when you try pointing the symbolic ref directly to the blob using `git update-ref`?
Oops! Turns out that when you reference a symbolic ref, it acts as if you had specified the ref it points to. To de-symbolic-ize it, use the `--no-deref` option directly after `update-ref`!
Weird, huh?

View file

@ -1 +0,0 @@
git update-ref --no-deref refs/fries "$BLOB2"

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@ -1,4 +0,0 @@
BLOB1=$(echo delicious | git hash-object -w --stdin)
BLOB2=$(echo very | git hash-object -w --stdin)
git update-ref refs/curly "$BLOB1"
git symbolic-ref refs/fries refs/curly

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@ -1,2 +0,0 @@
git symbolic-ref refs/fries && return 1
test "$(git show-ref -s refs/fries)" = "035e2968dafeea08e46e8fe6743cb8123e8b9aa6"

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@ -0,0 +1,35 @@
[description]
After carefully building the index we want, it would be nice to save a permanent snapshot of it, right?
This is what the second type of objects is for: trees! You can convert the index into a tree using
git write-tree
Try it! :)
[congrats]
Nice!
Can you make a different tree? Modify the index, then call `git write-tree` again!
[setup]
echo "file 1" > file1
echo "file 2" > file2
echo "file 3" > file3
git add .
[setup goal]
echo "file 1" > file1
echo "file 2" > file2
echo "file 3" > file3
git add .
git write-tree
[win]
git cat-file -p 21a638f28022064c1f1df20844278b494d197979

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@ -1,3 +0,0 @@
Nice!
Can you make a different tree? Modify the index, then call `git write-tree` again!

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@ -1,7 +0,0 @@
After carefully building the index we want, it would be nice to save a permanent snapshot of it, right?
This is what the second type of objects is for: trees! You can convert the index into a tree using
git write-tree
Try it! :)

View file

@ -1 +0,0 @@
git write-tree

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@ -1,4 +0,0 @@
echo "file 1" > file1
echo "file 2" > file2
echo "file 3" > file3
git add .

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@ -1 +0,0 @@
git cat-file -p 21a638f28022064c1f1df20844278b494d197979

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@ -1,3 +1,25 @@
[description]
Trees can also point to other trees! This way, they can describe nested directory structures.
When you add a file inside of a directory to the index, and then call `git write-tree`, it will create a nested tree for the directory, and attach the blob to it.
To solve this level, build a little stick figure, as shown on the left - a tree that points to two blobs, as well to a tree that points to two blobs.
[setup]
[setup goal]
echo "I'm the left arm" > arm1
echo "I'm the right arm" > arm2
mkdir hip
echo "I'm the left leg" > hip/leg1
echo "I'm the right leg" > hip/leg2
git add .
git write-tree
[win]
TREES=$(git cat-file --batch-check='%(objectname) %(objecttype)' --batch-all-objects | grep tree | cut -f1 -d" ")
for OUTER_TREE in $TREES; do

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@ -1,5 +0,0 @@
Trees can also point to other trees! This way, they can describe nested directory structures.
When you add a file inside of a directory to the index, and then call `git write-tree`, it will create a nested tree for the directory, and attach the blob to it.
To solve this level, build a little stick figure, as shown on the left - a tree that points to two blobs, as well to a tree that points to two blobs.

View file

@ -1,7 +0,0 @@
echo "I'm the left arm" > arm1
echo "I'm the right arm" > arm2
mkdir hip
echo "I'm the left leg" > hip/leg1
echo "I'm the right leg" > hip/leg2
git add .
git write-tree

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@ -0,0 +1,51 @@
[description]
As soon as you have some tree objects, you can always read them and set the index exactly to their content! Unsurprisingly, the command is called
git read-tree <tree>
For <tree>, you can provide the hash of any tree object - you can right-click one to insert its hash into the terminal!
Try reading some of the trees in this repository into the index!
[setup]
EMPTY_TREE=$(git write-tree)
echo "file 1" > file1
echo "file 2" > file2
git add .
git write-tree
rm *
echo "file A" > fileA
echo "file B" > fileB
echo "file C" > fileC
git add .
TRIPLE_TREE=$(git write-tree)
git read-tree "$EMPTY_TREE"
[setup goal]
EMPTY_TREE=$(git write-tree)
echo "file 1" > file1
echo "file 2" > file2
git add .
git write-tree
rm *
echo "file A" > fileA
echo "file B" > fileB
echo "file C" > fileC
git add .
TRIPLE_TREE=$(git write-tree)
git read-tree "$EMPTY_TREE"
git read-tree "$TRIPLE_TREE"
[win]
test "$(git ls-files | wc -l)" -gt 0

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@ -1,7 +0,0 @@
As soon as you have some tree objects, you can always read them and set the index exactly to their content! Unsurprisingly, the command is called
git read-tree <tree>
For <tree>, you can provide the hash of any tree object - you can right-click one to insert its hash into the terminal!
Try reading some of the trees in this repository into the index!

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