install

#!/usr/bin/env python

import os
import time
import yaml
import shutil

def install_link(target, link, **kwargs):
    """install symlinks, backing up existing files"""
    backupdir = os.path.expanduser('~/.config/dotfiles/backups')
    backupext = '.bak'
    if kwargs['backupext']:
        backupext = kwargs['backupext']

    if not os.path.islink(link) or not os.path.samefile(link, target):
        if not os.path.exists(backupdir):
            os.mkdir(backupdir)

        linkfile = os.path.basename(link)
        print "backing up existing file {}".format(linkfile)
        try:
            # TODO: if a symlink, just copy the symlink
            backupfile = "{}/{}{}".format(backupdir, linkfile, backupext)
            if os.stat(link):
                shutil.copy2(link, backupfile)
                os.unlink(link)
        except IOError as e:
            print("(skip) unable to backup {}".format(link))
            return
        except OSError as e:
            # no file means we don't need to back it up
            pass

        print("linking {} -> {}".format(target, link))
        os.symlink(target, link)
    else:
        print("(skip) link {} already installed...".format(link))


if __name__ == '__main__':
    configdir = os.path.dirname(os.path.realpath(__file__))
    backupext = ".bak-{}".format(time.strftime("%Y%m%d%H%M%S"))

    with open("install.yml", 'r') as stream:
        try:
            installdata = yaml.load(stream)
        except yaml.YAMLError as exc:
            print(exc)
            exit(1)

    for installdir in installdata.keys():
        realdir = os.path.expanduser(installdir)
        for link in installdata[installdir]:
            if type(link) == type(str()):
                linkpath = "{}/{}".format(realdir, link)
                targetpath = "{}/{}".format(configdir, link)
            elif type(link) == type(dict()):
                linkpath = "{}/{}".format(realdir, link['link'])
                targetpath = "{}/{}".format(configdir, link['target'])

            install_link(targetpath, linkpath, backupext=backupext)