git-is-branch-remote

#!/usr/bin/env bash

app_name="$(basename "${BASH_SOURCE[0]}")"
app_dir="$(dirname "${BASH_SOURCE[0]}")"

print_help() {
	expand -t 4 << EOF
Usage:
	$app_name <BRANCH...>
		Returns 0 if the branch(es) refer to a remote branch.

Options:
	-q, --quiet
		Suppress output.

	-?, --help
		Show this help information and exit.
EOF
}

quiet=0

args=()

for ((i = 1; i <= $#; i++)); do
	opt="${!i}"
	case "$opt" in
		-q|--quiet)
			quiet=1
			;;
		-\?|--help)
			print_help
			exit 0
			;;
		--)
			args+=("${@:i+1}")
			break
			;;
		-*)
			echo "$app_name: [Error] Unknown option: $1" >&2
			exit 1
			;;
		*)
			args+=("$opt")
			;;
	esac
done

if [[ ${#args[@]} -eq 0 ]]; then
	echo "$app_name: [Error] No branch is given." >&2
	echo "Try '$app_name -?' for more information." >&2
	exit 2
fi

git rev-parse --git-dir > /dev/null &&
result=0
for arg in "${args[@]}"; do
	full_name="$(git rev-parse --quiet --verify --symbolic-full-name "$arg")"
	if [[ "$full_name" == refs/remotes/* ]]; then
		[[ quiet -eq 0 ]] && echo "$arg: yes"
	elif [[ "$full_name" == refs/heads/* ]]; then
		[[ quiet -eq 0 ]] && echo "$arg: no"
		result=1
	else
		echo "$app_name: [Warning] Not a branch: $arg" >&2
		result=2
	fi
done

exit "$result"