Convert .gitmodules into a parsable format for iteration using Bash - bash

Question

Background
I would like to make a shell function that takes .gitmodules and iterates over each module executing certain commands based off of each submodules properties (e.g. <PATH> or <URL> or <BRANCH>).
➡️ The default format of .gitmodules:
[submodule "PATH"]
path = <PATH>
url = <URL>
[submodule "PATH"]
path = <PATH>
url = <URL>
branch = <BRANCH>
➡️ Pseudocode:
def install_modules() {
modules = new list
fill each index of the modules list with each submodule & its properties
iteratate over modules
if module # 'path' contains a specified 'branch':
git submodule add -b 'branch' 'url' 'path'
else:
git submodule add 'url' 'path'
}
⚠️ Current install_modules()
# currently works for grabbing the first line of the file
# doesn't work for each line after.
install_modules() {
declare -A regex
regex["module"]='\[submodule "(.*)"\]'
regex["url"]='url = "(.*)"'
regex["branch"]='branch = "(.*)"'
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
cat < ".gitmodules" | while read -r LINE; do
if [[ $LINE =~ ${regex[module]} ]]; then
PATH=${BASH_REMATCH[1]}
echo "$PATH"
fi
done
}

Answer 1

.gitmodules is a .gitconfig-like file so you can use git config to read it. For example, read all values from a .gitmodules, split values by = (key=value), and split keys by .:
git config -f .gitmodules -l | awk '{split($0, a, /=/); split(a[1], b, /\./); print b[1], b[2], b[3], a[2]}'
git config -f .gitmodules -l prints something like
submodule.native/inotify_simple.path=native/inotify_simple
submodule.native/inotify_simple.url=https://github.com/chrisjbillington/inotify_simple
and awk output would be
submodule native/inotify_simple path native/inotify_simple
submodule native/inotify_simple url https://github.com/chrisjbillington/inotify_simple

Answer 2

With a little help from #phd and Restore git submodules from .gitmodules (which #phd pointed me towards), I was able to construct the function that I needed.
install_submodules()
⚠️ Note: Assume $REPO_PATH is declared & initialized.
⚠️ My answer is an adaptation from https://stackoverflow.com/a/53269641/5290011.
install_submodules() {
git -C "${REPO_PATH}" config -f .gitmodules --get-regexp '^submodule\..*\.path$' |
while read -r KEY MODULE_PATH
do
# If the module's path exists, remove it.
# This is done b/c the module's path is currently
# not a valid git repo and adding the submodule will cause an error.
[ -d "${MODULE_PATH}" ] && sudo rm -rf "${MODULE_PATH}"
NAME="$(echo "${KEY}" | sed 's/^submodule\.\(.*\)\.path$/\1/')"
url_key="$(echo "${KEY}" | sed 's/\.path$/.url/')"
branch_key="$(echo "${KEY}" | sed 's/\.path$/.branch/')"
URL="$(git config -f .gitmodules --get "${url_key}")"
BRANCH="$(git config -f .gitmodules --get "${branch_key}" || echo "master")"
git -C "${REPO_PATH}" submodule add --force -b "${BRANCH}" --name "${NAME}" "${URL}" "${MODULE_PATH}" || continue
done
git -C "${REPO_PATH}" submodule update --init --recursive
}