From a48d4eaddf282f1dda54a2b83d98710394063a3d Mon Sep 17 00:00:00 2001
From: Jack Jansen <jack.jansen@cwi.nl>
Date: Sun, 9 Sep 2001 00:35:19 +0000
Subject: [PATCH] Minimal module to decode AppleSingle files (the way resource
 files are stored in the CVS repository). It can either decode resource/data
 forks in the standard Mac way or decode only the resource fork but store the
 result in the data fork (the MacOSX preferred way). Finder info and all other
 stuff is ignored.

---
 Mac/Lib/applesingle.py | 101 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)
 create mode 100644 Mac/Lib/applesingle.py

diff --git a/Mac/Lib/applesingle.py b/Mac/Lib/applesingle.py
new file mode 100644
index 0000000000..bee3318821
--- /dev/null
+++ b/Mac/Lib/applesingle.py
@@ -0,0 +1,101 @@
+# applesingle - a module to decode AppleSingle files
+import struct
+import MacOS
+import sys
+
+Error="applesingle.Error"
+
+verbose=0
+
+# File header format: magic, version, unused, number of entries
+AS_HEADER_FORMAT="ll16sh"
+AS_HEADER_LENGTH=26
+# The flag words for AppleSingle
+AS_MAGIC=0x00051600
+AS_VERSION=0x00020000
+
+# Entry header format: id, offset, length
+AS_ENTRY_FORMAT="lll"
+AS_ENTRY_LENGTH=12
+
+# The id values
+AS_DATAFORK=1
+AS_RESOURCEFORK=2
+AS_IGNORE=(3,4,5,6,8,9,10,11,12,13,14,15)
+
+def decode(input, output, resonly=0):
+	if type(input) == type(''):
+		input = open(input, 'rb')
+	# Should we also test for FSSpecs or FSRefs?
+	header = input.read(AS_HEADER_LENGTH)
+	print `header`
+	try:
+		magic, version, dummy, nentry = struct.unpack(AS_HEADER_FORMAT, header)
+	except ValueError, arg:
+		raise Error, "Unpack header error: %s"%arg
+	if verbose:
+		print 'Magic:   0x%8.8x'%magic
+		print 'Version: 0x%8.8x'%version
+		print 'Entries: %d'%nentry
+	if magic != AS_MAGIC:
+		raise Error, 'Unknown AppleSingle magic number 0x%8.8x'%magic
+	if version != AS_VERSION:
+		raise Error, 'Unknown AppleSingle version number 0x%8.8x'%version
+	if nentry <= 0:
+		raise Error, "AppleSingle file contains no forks"
+	headers = [input.read(AS_ENTRY_LENGTH) for i in range(nentry)]
+	didwork = 0
+	for hdr in headers:
+		try:
+			id, offset, length = struct.unpack(AS_ENTRY_FORMAT, hdr)
+		except ValueError, arg:
+			raise Error, "Unpack entry error: %s"%arg
+		if verbose:
+			print 'Fork %d, offset %d, length %d'%(id, offset, length)
+		input.seek(offset)
+		if length == 0:
+			data = ''
+		else:
+			data = input.read(length)
+		if len(data) != length:
+			raise Error, 'Short read: expected %d bytes got %d'%(length, len(data))
+		if id == AS_DATAFORK:
+			if verbose:
+				print '  (data fork)'
+			if not resonly:
+				didwork = 1
+				fp = open(output, 'wb')
+				fp.write(data)
+				fp.close()
+		elif id == AS_RESOURCEFORK:
+			didwork = 1
+			if verbose:
+				print '  (resource fork)'
+			if resonly:
+				fp = open(output, 'wb')
+			else:
+				fp = MacOS.openrf(output, 'wb')
+			fp.write(data)
+			fp.close()
+		elif id in AS_IGNORE:
+			if verbose:
+				print '  (ignored)'
+		else:
+			raise Error, 'Unknown fork type %d'%id
+	if not didwork:
+		raise Error, 'No useful forks found'
+
+def _test():
+	if len(sys.argv) < 3 or sys.argv[1] == '-r' and len(sys.argv) != 4:
+		print 'Usage: applesingle.py [-r] applesinglefile decodedfile'
+		sys.exit(1)
+	if sys.argv[1] == '-r':
+		resonly = 1
+		del sys.argv[1]
+	else:
+		resonly = 0
+	decode(sys.argv[1], sys.argv[2], resonly=resonly)
+	
+if __name__ == '__main__':
+	_test()
+	
\ No newline at end of file
-- 
2.40.0