Copy files from one git repository to another with all history

instruction.sh

# https://blogs.s-osg.org/retain-history-moving-files-git-repositories/
# http://gbayer.com/development/moving-files-from-one-git-repository-to-another-preserving-history/

### 1
vim /tmp/git_script.sh

#>>>>>>
#!/bin/bash

mkdir -p newroot/
mkdir -p newroot/src

# Pipe output to silence "file not found" warnings.

mv old.file newroot/ 2>/dev/null
mv src/another.old.file newroot/src/ 2>/dev/null
true
#<<<<<<


### 2
git clone git@oldrepo /tmp/oldrepo
cd /tmp/oldrepo
git checkout branch_if_needed_or_master
git filter-branch -f --prune-empty --tree-filter /tmp/git_script.sh HEAD
git filter-branch --prune-empty -f --subdirectory-filter newroot

### 3
git clone git@newrepo /tmp/newrepo
cd /tmp/newrepo
git remote add /tmp/oldrepo
git pull old_repo branch_if_needed_or_master