Helper script to push and pull my games save states

sync_saves.sh

#!/usr/bin/env bash

set -eo pipefail

# echo errors massages and exit.
function error (){
    echo "ERROR: ${*}"
    exit 1
}

# echo logs
function log (){
    echo "LOG: ${*}"
}

# return "true" if the repos has changes
# and "false" if not.
function check_changes (){
    git --git-dir="${GIT_DIR}" --work-tree="${GIT_WORK_TREE}" diff --quiet --exit-code &&  echo "false" || echo "true"
}

# Run git in the desired worktree
function run_git (){
    local git_cmd branch 
    git_cmd="${1}"
    branch="${2}"
    git --git-dir="${GIT_DIR}" --work-tree="${GIT_WORK_TREE}" \
    "${git_cmd}" origin "$branch"
}

# Check if the repo has new changes and commit then.
function commit_save_files (){
    local files_to_commit
    files_to_commit=$(git \
            --git-dir="${GIT_DIR}" \
            --work-tree="${GIT_WORK_TREE}" \
            status --porcelain=v1 | grep -Po 'states.+' | xargs echo)
    git --git-dir="${GIT_DIR}" --work-tree="${GIT_WORK_TREE}" \
    add "${files_to_commit[*]}" 

    git --git-dir="${GIT_DIR}" --work-tree="${GIT_WORK_TREE}" \
    commit -m "savestate: ${files_to_commit[*]//states\//}" 
}

# Print help information.
function help_info (){
    cat << EOF
Sync savestates with github (huguito - 2021)

Usage:
    ./sync_saves.sh ( push | pull ) GIT_LOCAL_REPO

Options
    push    Push will commit changes made locally (if any)
            and commit then to the git remote repo.
    pull    Pull will donwload updates changes locally from git.
EOF
    exit 1
}

function main (){
    
    [ -z "${*:1}" ] && help_info
    
    local git_command repo_location branch
    git_command="${1}"
    repo_location="$(readlink -f ${2})"
    branch="${3:-master}"

    if [ -d "${repo_location}" ];then
        local GIT_DIR GIT_WORK_TREE
        GIT_DIR="$( echo "${repo_location}" | sed 's/\/$//' )/.git"
        GIT_WORK_TREE="${repo_location}"
    else
        error "repo do not exists !!!"
    fi

    case "${git_command}" in
        
        "push")
            "$(check_changes)" && commit_save_files || {
                echo "LOG: No files to be commited."
            }
            run_git "${git_command}" "$branch" 
            ;;
        "pull")
            run_git "${git_command}" "$branch" 
            ;;
        *)
            help_info
            ;;
    esac
}       

ARGS=("$@")
main "${ARGS[@]}"