#!/usr/bin/env python3# This helper script makes it easy to use a passwd or group file to map values# in a LOCAL transfer.  For instance, if you mount a backup that does not have# the same passwd setup as the local machine, you can do a copy to/from the# backup area as follows and get the differing ID values mapped just like a# remote transfer to/from the backed-up machine would do:## rsync -av --usermap=`idmap --to /mnt/backup/etc/passwd` \#           --groupmap=`idmap --to /mnt/backup/etc/group` \#           /some/src/ /mnt/backup/some/dest/## rsync -av --usermap=`idmap --from /mnt/backup/etc/passwd` \#           --groupmap=`idmap --from /mnt/backup/etc/group` \#           /mnt/backup/some/src/ /some/dest/ import re, fileinput, argparse NAME_ID_RE = re.compile(r'^(\w+):[^:]+:(\d+)') def main():    maps = [ ]    for line in fileinput.input(args.files):        m = NAME_ID_RE.match(line)        if not m:            continue        if args.to:            pair = (m[1], m[2])        else:            pair = (m[2], m[1])        maps.append(':'.join(pair))    print(','.join(maps))  if __name__ == '__main__':    parser = argparse.ArgumentParser(description="Output usermap or groupmap args for rsync.", add_help=False)    action = parser.add_argument_group()    action = parser.add_mutually_exclusive_group(required=True)    action.add_argument("--from", action="store_true", help="Output the map for use on the sending side.")    action.add_argument("--to", action="store_true", help="Output the map for use on the receiving side.")    parser.add_argument("--help", "-h", action="help", help="Output this help message and exit.")    parser.add_argument("files", metavar="FILE", default='-', nargs='*', help="The file(s) that hold the name & id pairs. Defaults to stdin.")    args = parser.parse_args()    main() # vim: sw=4 et