merger - a command line tool for resolving merge conflicts with p4merge

merger

#!/usr/bin/env python
#
# Author: wbbradley
# Created: Originally written in Perl in 2010
# Edited: Rewritten in Python in 2014
#
# You'll need to have P4Merge installed. It's free, and
# you can find it here:
# http://lmgtfy.com/?q=P4Merge+Tool+Download
#

from subprocess import Popen, PIPE, STDOUT


def system(cmd, shell=False):
    if isinstance(cmd, (str, unicode)):
        print "Running {}".format(cmd)
    else:
        print "Running {}".format(' '.join(cmd))

    proc = Popen(cmd, shell=shell, stderr=STDOUT, stdout=PIPE)
    out, err = proc.communicate()
    if err:
        raise Exception('Error {} running {}'.format(err, cmd))

    return out

merges = {}

lines = system(['git', 'ls-files', '-u']).split('\n')
for line in lines:
    line = line.split()
    if line:
        attrs, sha, obj_type, filename = line
        merges[filename] = merges.get(filename) or {}
        merges[filename][obj_type] = sha

for filename, objects in merges.iteritems():
    if len(objects.keys()) == 3:
        head_file = "/var/tmp/head_file"
        merge_file = "/var/tmp/merge_file"
        ancestor_file = "/var/tmp/ancestor_file"
        system("git show {} > {}".format(objects['1'], ancestor_file), shell=True)
        system("git show {} > {}".format(objects['2'], head_file), shell=True)
        system("git show {} > {}".format(objects['3'], merge_file), shell=True)

        p4merge_cmd = [
            "/Applications/p4merge.app/Contents/Resources/launchp4merge",
            ancestor_file, head_file, merge_file, filename
        ]
        system(p4merge_cmd)
        print "+"*79
        print "Here's the diff that remains from your merge of {}".format(filename)
        print system(['git', 'diff', '--', filename])
        key = raw_input("Would you like to run 'git add {}'? [Ynpq]".format(filename))
        if key in ['Y', 'y', 'p'] or key == '':
            print system(['git', 'add', '-p' if key == 'p' else '', filename])
            print system("git status | grep both", shell=True)
        else:
            if key == 'q':
                system("git status | grep both", shell=True)
                sys.exit()
    else:
        print "Skipping merge of {}...".format(filename)