Copy a single file or directory into BFS disk image

cp2bfs

#!/bin/sh

# Simple script that mounts specified BFS disk image file to temporary directory,
# copies specified file there, unmounts the image and removes temporary directory.
# Usage: cp2bfs my-file-to-copy my-test-disk.bfs

MOUNTDIR=
FROM=$1
BFSFILE=$2

if [ -z "$BFSFILE" ] || [ ! -f "$BFSFILE" ] ; then
	echo "BFS image file not specified" >&2
	exit 1
fi

cleanup () {
	if [ -z "$MOUNTDIR" ] || [ ! -d "$MOUNTDIR" ] ; then
		return
	fi

	unmount "$MOUNTDIR" &>/dev/null || true
	rm -rf "$MOUNTDIR"
}

MOUNTDIR=$(mktemp -d)
trap 'cleanup' EXIT INT TERM

mount "$BFSFILE" "$MOUNTDIR" || (echo "Could not mount '$BFSFILE', are you sure it's valid?" >&2 && exit 1)
cp -a "$FROM" "$MOUNTDIR"