dev/subtree-hash

   1 #!/bin/sh
   2 """": # -*-python-*-
   3 bup_exec="$(dirname "$0")/bup-exec" || exit $?
   4 exec "$bup_exec" "$0" ${1+"$@"}
   5 """
   6
   7 from __future__ import absolute_import, print_function
   8 import os.path, sys
   9
  10 from bup.compat import argv_bytes, get_argvb
  11 from bup.helpers import handle_ctrl_c, readpipe
  12 from bup.io import byte_stream
  13 from bup import options
  14
  15
  16 optspec = """
  17 subtree-hash ROOT_HASH [PATH_ITEM...]
  18 --
  19 """
  20
  21 handle_ctrl_c()
  22
  23 o = options.Options(optspec)
  24 opt, flags, extra = o.parse_bytes(get_argvb()[1:])
  25
  26 if len(extra) < 1:
  27     o.fatal('must specify a root hash')
  28
  29 tree_hash = argv_bytes(extra[0])
  30 path = [argv_bytes(x) for x in extra[1:]]
  31
  32 while path:
  33     target_name = path[0]
  34     subtree_items = readpipe([b'git', b'ls-tree', b'-z', tree_hash])
  35     target_hash = None
  36     for entry in subtree_items.split(b'\0'):
  37         if not entry:
  38             break
  39         info, name = entry.split(b'\t', 1)
  40         if name == target_name:
  41             _, _, target_hash = info.split(b' ')
  42             break
  43     if not target_hash:
  44         print("Can't find %r in %s" % (target_name, tree_hash.decode('ascii')),
  45               file=sys.stderr)
  46         break
  47     tree_hash = target_hash
  48     path = path[1:]
  49
  50 if path:
  51     sys.exit(1)
  52
  53 sys.stdout.flush()
  54 out = byte_stream(sys.stdout)
  55 out.write(tree_hash + b'\n')