.git-svn-externals.example

https://yoursvnserver.example.com/framework lib/framework
https://someotherlibrary.example.com/framework lib/other_framework

git-svn-update-externals

#!/usr/bin/env bash

# Operate on the current working directory.
PROJECT_DIR="$(pwd)"

display_usage() {
    cat <<HELPTEXT
Usage: git-svn-update-externals

Looks for a file named .git-svn-externals in the current working directory
and extracts the SVN URL and local checkout path from it.

If the SVN Repository is already checked out in the local path, then
it makes a git-svn-rebase, otherwise it does a git-svn-clone into
the local path.

The .git-svn-externals file is a simple textfile where each line
consists of a SVN URL and the path where a local copy should be
checked out. This two values are separated by a space.

HELPTEXT
}

clone_repo() {
    local svn_url="$1"
    local local_path="$2"

    if [ $# -eq 0 ]; then
        echo "clone_repo: Not enough arguments" >&2
        return 1
    fi

    echo "Checkout $svn_url into $local_path"
    git svn clone --stdlayout "$svn_url" "$local_path"
}

rebase_repo() {
    local repo="$1"

    cd "$repo"
    git svn rebase
    cd - > /dev/null
}

is_git_repo() {
    local dir="$1"
    
    if [ -d "$dir/.git" ]; then
        return 0
    else
        return 1
    fi
}

if [ "$1" = "-h" ] || [ "$1" = "--help" ]; then
    display_usage
    exit
fi

if [ ! -f "$PROJECT_DIR/.git-svn-externals" ]; then
    echo "No .git-svn-externals file found in the current working directory." >&2
    exit 1
fi

while read -r svn_url local_path
do
    if is_git_repo "$local_path"
    then
        echo "Updating $local_path"
        rebase_repo "$PROJECT_DIR/$local_path"
        echo "Done."
    else
        clone_repo "$svn_url" "$PROJECT_DIR/$local_path"
        echo "Done."
    fi
done < "$PROJECT_DIR/.git-svn-externals"