Move files to a different repo with history

git-move.sh

#! /bin/bash
# Usage:
# ./git-move.sh path1/ path2/...  path/to/destination/repo
args=("$@")

# All but last argument:
paths=("${args[@]::${#args[@]}-1}")
# Last argument:
dest="${args[${#args[@]}-1]}"

echo "creating patch for paths: ${paths[@]}"
echo "moving to destination: $dest"
# Iterate path arguments and append to tmpfile:
for p in "${paths[@]}"
do
   git log --name-only --pretty="format:" --follow -- "$p" >> __LOGNAMES_TMP1290
done
cat __LOGNAMES_TMP1290 | sort -u | \
 xargs git log --pretty=email --patch-with-stat --reverse --full-index --binary -m --first-parent -- > "$dest/_patch_"
trash __LOGNAMES_TMP1290
echo "moving to destination repo at $dest"
cd "$dest"
echo "applying patch"
git am -s --committer-date-is-author-date < _patch_
trash _patch_
echo "OK"

Based on this answer on Stack.

Notes:

• This preserves the date of each commit, but:
  • git log will show commits in the order they are made, not date order
  • This can be solved with a rebase, I think
  • Possibly with some sort of flag? log is monstrously complex...
• Best behaved copying onto a clean repo, so useful for breaking out some code into its own project
  • If you're copying it onto an existing repo, make sure you don't have any name collisions, or things will get messy
  • Probably a good idea to make a branch if copying onto an existing repo, at a bare minimum.
  • If there are name collisions, move them out of the way with git mv, commit, run script, hope for the best
  • This script has been tried onto a clean git init repo only
• Results not guaranteed!
• trash can be replaced with rm, or better yet, install it. Nondestructive removal is a nice thing to have.