In Git, the “git ls-tree” command allows you to list the contents of a tree object. A tree object represents a directory in the Git repository and contains references to files and other sub-directories within that directory.
When you run the “git ls-tree” command in your terminal or command prompt, you provide the hash or the name of a tree object as an argument. Git will then retrieve the contents of that tree object and display information about each file or sub-directory within it.
The output of “git ls-tree” includes the following information for each entry in the tree object:
- File Mode: A four-digit number representing the file mode of the entry. It indicates whether the entry is a regular file, a symbolic link, or a sub-directory, among other possibilities.
- Object Type: The type of the object referenced by the entry. It can be a blob (file), tree (sub-directory), commit (commit object), or tag (annotated tag).
- Object Hash: The unique identifier (SHA-1 hash) of the object referenced by the entry. For files (blobs) and sub-directories (trees), the hash corresponds to their individual objects.
- File Name: The name of the file or sub-directory.
By default, “git ls-tree” displays the contents of a tree recursively, meaning it includes the contents of sub-directories within the tree object. However, you can use command-line options to limit the depth of recursion or display only the top-level entries.
The “git ls-tree” command is useful when you want to examine the contents of a directory at a specific point in history. It allows you to see the files and sub-directories within a tree object, along with their respective object types and hashes. This information can be helpful when investigating the structure of a repository, understanding changes made to specific directories, or retrieving files from a specific commit.
git ls-tree Command Examples
1. List the contents of the tree on a branch:
# git ls-tree branch_name
2. List the contents of the tree on a commit, recursing into subtrees:
# git ls-tree -r commit_hash
3. List only the filenames of the tree on a commit:
# git ls-tree --name-only commit_hash
Overall, “git ls-tree” is a handy command that provides insights into the contents of a tree object in a Git repository. It helps you explore the file and directory structure at a given point in history, facilitating your understanding of the repository’s organization and changes over time.