update_git_repos.sh

#!/usr/bin/env bash
# Fast-forward every git repo immediately under $PWD on its default branch.
# Skips repos with uncommitted changes, no `origin` remote, or a `.git` file
# (i.e. worktrees — only the host repo gets updated).

yellow=$'\e[33m' red=$'\e[31m' green=$'\e[32m' reset=$'\e[0m'

shopt -s nullglob
for repo in */.git/; do
    dir=${repo%/.git/}
    printf '\n%s%s%s\n' "$yellow" "$dir" "$reset"
    (
        cd "$dir" || exit 1
        if ! git diff --quiet HEAD -- 2>/dev/null; then
            printf '  %sskipped — uncommitted changes%s\n' "$red" "$reset"
            exit 0
        fi
        default=$(git symbolic-ref --short refs/remotes/origin/HEAD 2>/dev/null)
        if [ -z "$default" ]; then
            printf '  %sskipped — no origin remote%s\n' "$red" "$reset"
            exit 0
        fi
        git checkout --quiet "${default#origin/}" \
          && git pull --ff-only --prune --quiet \
          || printf '  %sfast-forward failed%s\n' "$red" "$reset"
    )
done

printf '\n%sDone.%s\n' "$green" "$reset"