dircopy

#!/usr/bin/env python
"""Simple rsync wrapper for making directory images and synchronizing dirs.

USAGE
  dircopy [options] from1 from2 ... destination_dir

Make an image of all files/directories given in the command line to the last
argument given.

The last argument must be either an existing directory or a name which doesn't
exist in the filesystem. In the latter case, a directory will be created with
that name (a warning is issued). If the destination is given as a file, the
program aborts.

If the destination contains ':', all checks are ignored as this will be
treated by rsync as a remote transfer.  In this case, a '-e ssh' is
automatically added to the rsync options.  It has only been tested between
hosts which have been configured for password-less ssh logins.

By default, dircopy will make the destination look like the source, meaning
that any pre-existing files in the destination WILL BE DELETED if they are not
in the source. In order to synchronize two directories keeping the most recent
versions of each file, use the -sync option (see below).

dircopy uses rsync for the actual data transfer (so it's fast). Please see the
rsync manpage for all the relevant details on its use.


OPTIONS

All options can be abbreviated to their shortest non-ambiguous form.

  -dry-run, -n: this option is passed directly to rsync. It allows you to see
  what rsync would do without actually performing it. The same effect can be
  achieved using -rsoptions '-n', so this is just a convenience option.

  -help: print this message and exit.

  -debug: don't execute any system call, just print them.

  -logname <filename>: log output to this file. If logfile isn't given, the
  name .dircopy.log is used in the destination directory.

  -nolog: suppress logfile generation.

  -quiet: do not print anything to stdout (useful for cron jobs), but the
  logfile is still generated.

  -nodelete: override the default behavior and do NOT delete files which do
  not exist in the destination.  This has no effect if -sync is invoked.

  -rsoptions <string>: options to be passed verbatim to rsync. The whole
  string must be protected with single or double quotes (so it can be
  considered as a single element and not as separate options for dircopy).

  -sync: synchronize two directories by comparing timestamps. In this
  mode only two arguments can be given, dir1 and dir2. The process is:

   1) dir1 -> dir2. Files in dir2 newer than in dir1 are respected.
   2) dir2 -> dir1. Files in dir1 newer than in dir2 are respected.

  In this mode, files are not deleted from either directory. The process is
  completely symmetrical between dir1 and dir2. In both sync modes (see -Dsync
  below) a trailing '/' is appended to the directory names automatically. See
  the rsync manpage for details on the semantics of trailing '/' in directory
  names.

  -Dsync: similar to sync, but in step 1), files which do not exist in the
  source are deleted from the destination.

  USE WITH CARE. Files which exist in both directories will be properly
  synchronized by timestamp, but the process is NOT symmetrical between source
  and destination because of the deletion mechanism.

  -verbose: print all system calls to stdout.
"""
__author__  = 'Fernando Perez <fperez@colorado.edu>'
__date__    = 'Mon Nov 18 15:36:35 MST 2002'

#***************************************************************************
# Standard library modules
import os
import shutil
import subprocess
import subprocess as sp
import sys

from platform import platform
from time import ctime
from tempfile import mktemp


#***************************************************************************
# Class and function definitions

def system(cmd):
    if system.verbose or system.debug:
        print('***CMD***', cmd)
    if not system.debug:
        subprocess.call(cmd, shell=False)

system.verbose = False
system.debug = False


def init():
    """Initialization and command-line processing.

    It creates the global names:
     - sysx: instance of SystemExec, can be used for system calls.
     - system: alias to sysx.system.

    Returns a Struct with options and a list of positional arguments."""

    # Names and default values for command-line options
    import argparse
    parser = argparse.ArgumentParser(
        description='Sync two directories')
    for flag in ('dry-run n debug verbose quiet '
                 'sync Dsync keeplog nolog nodelete').split():
        parser.add_argument('--'+flag, action='store_true')
    parser.add_argument('--rsoptions', type=str, default='')
    parser.add_argument('--logname', type=str, default='')
    parser.add_argument('sources', type=str, nargs='+')
    parser.add_argument('dest', type=str)

    # Process command line.
    opt = parser.parse_args()
    #print(opt); import sys; sys.exit()  # dbg
    system.verbose = opt.verbose
    system.debug = opt.debug
    return opt


def print_transfer(log, src, dest):
    print('.'*78, file=log)
    print(src, '|--->', dest, file=log)
    print(file=log)
    log.flush()


def escape(s):
    return '"%s"' % s


def pipe(c1, c2):
    """
    Make a 2-command pipe, return the stdout/err of the 2nd command.

    Stdout/err of c1 are piped into stdin of c2.
    """
    if system.debug or system.verbose:
        print("P1:", c1)
        print("P2:", c2)
    if system.debug:
        return None, None

    p1 = sp.Popen(c1, stdout=sp.PIPE, stderr=sp.PIPE)
    p2 = sp.Popen(c2, stdin=p1.stdout)
    out, err = p2.communicate()
    p1.wait()
    return out, err


def append(new, old):
    """
    Append content of 'new' file onto 'old'
    """
    with open(old, 'a') as oldf, open(new, 'r') as newf:
        shutil.copyfileobj(newf, oldf)


def main():
    """Real logic goes here."""

    default_logname = '.dircopy.log'
    opt = init()

    # Positional arguments as lists
    cp_from = opt.sources  # list
    cp_to  = [opt.dest]  # original is a string

    # string versions for some checks
    sources_s = ''.join(cp_from)
    targets_s = opt.dest

    #print("from:", cp_from)  # dbg
    #print("to  :", cp_to)  # dbg
    #print("t from:", type(cp_from))  # dbg
    #print("t to  :", type(cp_to))  # dbg
    #sys.exit()  # dbg

    if ':' not in targets_s:
        # don't try to create directories across the network
        if not os.path.exists(targets_s):
            print("Destination directory %s doesn't exist. Creating it." % cp_to, file=sys.stderr)
            os.makedirs(targets_s)
        elif not os.path.isdir(targets_s):
            print('The last argument must be a directory.', file=sys.stderr)

    if opt.logname:
        logname = opt.logname
    else:
        #import pdb; pdb.set_trace() # dbg
        logname = os.path.join(cp_from[0], default_logname)
        print("logname:", logname)

    if opt.Dsync:
        opt.sync = 2

    print(f'DBG: cp_from: {cp_from}')  # dbg
    if opt.sync and not os.path.isdir(cp_from[0]):
        print('sync mode can only be invoked with two directories.',
              file=sys.stderr)

    # simplify the tricky semantics of /-terminated names in rsync
    if opt.sync:
        if os.path.isdir(sources_s):
            cp_from[0] = cp_from[0] + '/'
        cp_to[0] = cp_to[0] + '/'

    #print('fr:', cp_from)  # dbg
    #print('to:', cp_to)  # dbg

    if opt.dry_run or opt.n:
        opt.rsoptions += ' --dry-run'

    # Create logfile. We need to log to a temp file outside of the working
    # directories so it doesn't get clobbered when syncing
    log_tmpname = mktemp()
    teecmd = ['tee', '-a', log_tmpname]

    log = open(log_tmpname, 'a')
    start = ctime()
    header = "-"*78 + """
*** dircopy log
Starting    : %s
Called from : %s
Source      : %s
Destination : %s
Mode        : %s
rsync opts  : %s

Output of rsync:\
""" % (start, os.getcwd(), cp_from, cp_to,
       ['image', 'sync', 'Dsync - destructive sync'][opt.sync],
       opt.rsoptions)

    print(header, file=log)
    log.flush()  # so shell writes are properly ordered

    rscmd = ['rsync', '-avHs', '--update']
    if opt.rsoptions:
        rscmd.append(opt.rsoptions.strip('"'))
    if platform().startswith('Darwin'):
        rscmd.extend(['--xattrs', '--exclude', '.DS_Store',
                      '--exclude', '.localized'])
    if ':' in sources_s or ':' in targets_s:
        rscmd.extend(['-e', 'ssh'])

    if opt.sync:
        if opt.Dsync:
            rscmd.append('--delete')
        #print_transfer(log, cp_from, cp_to)  # dbg
        pipe(rscmd + cp_from + cp_to, teecmd)
        #print(file=log)   # dbg
        #print_transfer(log, cp_to, cp_from)  # dbg
        pipe(rscmd + cp_to + cp_from, teecmd)
    else:
        if not opt.nodelete:
            rscmd.append('--delete')
        #print_transfer(log, cp_from, cp_to)
        #print("rscmd: {}\nfrom :{}\nto   :{}".format(rscmd, cp_from, cp_to)) # dbg
        pipe(rscmd + cp_from + cp_to, teecmd)

    print("\n*** dircopy started  :", start, file=log)
    print("*** dircopy finished :", ctime(), file=log)
    log.close()

    # update the logfile
    if not opt.nolog:
        try:
            if opt.keeplog:
                append(log_tmpname, logname)
            else:
                os.rename(log_tmpname, logname)
            print('Log info left in:', logname)
        except OSError:
            # moving across filesystem boundaries fails in linux
            if ':' not in logname:
                # Don't try to copy the logfile over ssh
                if opt.keeplog:
                    append(log_tmpname, logname)
                else:
                    shutil.copy2(log_tmpname, logname)
                print('Log info left in:', logname)
            os.unlink(log_tmpname)
        # the logfile won't be properly synced, but we can't do it over ssh
        if opt.sync and not (':' in targets_s or ':' in sources_s):
            log_dir = os.path.dirname(os.path.abspath(logname))
            if os.path.samefile(log_dir, sources_s):
                shutil.copy2(logname, targets_s)
            elif os.path.samefile(log_dir, targets_s):
                shutil.copy2(logname, sources_s)

    # Finished
    print('Dircopy finished:', ctime())


# Script entry point
if __name__ == '__main__':
    main()