git-pickdir

Extract one or more subdirectories from the current Git repository into a new repository, with contents flattened to the root and history rewritten so only those paths remain.

Requirements

• Bash (with set -euo pipefail support)
• git ≥ 2.x
• git-filter-repo (install) — must be on your PATH

Usage

git-pickdir [OPTIONS] REPODIR SUBDIRS...

• REPODIR — Target directory for the new repository (must not already exist).
• SUBDIRS... — One or more repository-relative subdirectory paths to extract.

Example

git-pickdir ../newrepo src/lib include/common

Creates ../newrepo containing only the contents of src/lib and include/common, at the root of the new repo, with history preserved for those paths.

Install

Put git-pickdir somewhere on your PATH, e.g.:

cp git-pickdir ~/bin/
# or
sudo cp git-pickdir /usr/local/bin/

Errors (exit non-zero, message to stderr)

The tool exits with an error if:

• Not run inside a Git repository
• Repository has no commits
• REPODIR already exists
• No SUBDIRS provided
• Any SUBDIR does not exist at HEAD
• Any SUBDIR is an absolute path or contains ..
• One subdir is a prefix of another (e.g. src and src/lib)
• Flattening would produce a filename collision (same name from different subdirs)
• git-filter-repo is not installed or not in PATH
• Any Git or filter-repo command fails
• No files remain after filtering

Behavior

• Repo root is detected with git rev-parse --show-toplevel; all logic is based on that root.
• Copy vs clone: If the repo is “fresh” (no loose objects, no remotes), the tool uses cp -a for speed; otherwise it uses git clone --no-local to avoid hardlinks.
• History is rewritten with git filter-repo so only the chosen paths exist and are moved to the repository root.
• The new repository is independent: no remotes, no hardlinks to the original.