Recursively finds dependencies in Mach-O binaries, output a tree-like structure or a graph file via Graphviz

RecOTool.py

# RecOTool.py -- Recursively finds dependencies in Mach-O binaries
#
# This is free and unencumbered software released into the public domain.
#
# Run with Python2... I don't know why do not works with 3....
#
# Usage
# python RecOTool.py /usr/bin/something -o deps.png (if Graphviz installed)
# python RecOTool.py /usr/bin/something -v (output only text, verbose mode
#                                           enabled)
# python RecOTool.py /usr/bin/something -v -o deps.png
# (outputs a text output & a graph file)

import sys
import subprocess
import argparse

done = set()
dotfile = None
args = None
id = 0

def printid(s):
	print(' '*id + s)

def add_dot(n1, n2):
	s1 = n1.split("/")[-1]
	s2 = n2.split("/")[-1]
	dotfile.write("\"{}\" -> \"{}\"\n".format(s1, s2))

def otool(s):
	if args.verbose:
		printid('otooling {}'.format(s))
		printid('--------')
	libs = set()
	o = subprocess.Popen(['/usr/bin/otool', '-L', s], stdout=subprocess.PIPE)
	for l in o.stdout:
		if l[0] == '\t':
			libs.add(l.split(' ', 1)[0][1:])
	return libs

def search(targ):
	global id
	global done

	libs = otool(targ)
	libs.difference_update(done)

	for l in libs:
		if args.verbose:
			printid(l)
		done.add(l)
		add_dot(targ, l)

		id=id+args.indent
		search(l)
		id=id-args.indent

def parse_args():
	p = argparse.ArgumentParser(
		description='Recursively finds dependencies in a Mach-O binary')

	p.add_argument("binary", type=str, help="Binary to be analyzed")
	p.add_argument('-v', '--verbose', default=False, action="store_true", 
		help='Enable verbose output')
	p.add_argument('-i', '--indent', help='Set indent level (default=4)',
		type=int, default=4)
	p.add_argument('-d', '--dot', help='Set output dot file', type=str,
		default='out.dot')
	p.add_argument('-o', '--output',
		help='Enable and set output image filename (PNG)', type=str,
		default='none')
	
	return p.parse_args()

def main():
	global dotfile
	global args
	args = parse_args()

	# Open dot file and search recursively
	dotfile = open(args.dot, "w+")
	dotfile.write("digraph deps {\n")
	search(args.binary)
	dotfile.write("}\n")
	dotfile.close()

	# Output PNG file
	if args.output != 'none':
		try:
			subprocess.call(['dot', '-Tpng', args.dot, '-o', args.output])
		except:
			sys.stderr.write(
				"Unable to create graph, please check if Graphviz is "
				"properly installed!\n")

if __name__ == "__main__":
	main()