1 2#------------------------------------------------------------------------------ 3# $File: cafebabe,v 1.8 2009/09/19 16:28:08 christos Exp $ 4# Cafe Babes unite! 5# 6# Since Java bytecode and Mach-O fat-files have the same magic number, the test 7# must be performed in the same "magic" sequence to get both right. The long 8# at offset 4 in a mach-O fat file tells the number of architectures; the short at 9# offset 4 in a Java bytecode file is the JVM minor version and the 10# short at offset 6 is the JVM major version. Since there are only 11# only 18 labeled Mach-O architectures at current, and the first released 12# Java class format was version 43.0, we can safely choose any number 13# between 18 and 39 to test the number of architectures against 14# (and use as a hack). Let's not use 18, because the Mach-O people 15# might add another one or two as time goes by... 16# 170 belong 0xcafebabe 18!:mime application/x-java-applet 19>4 belong >30 compiled Java class data, 20>>6 beshort x version %d. 21>>4 beshort x \b%d 22# Which is which? 23#>>4 belong 0x032d (Java 1.0) 24#>>4 belong 0x032d (Java 1.1) 25>>4 belong 0x002e (Java 1.2) 26>>4 belong 0x002f (Java 1.3) 27>>4 belong 0x0030 (Java 1.4) 28>>4 belong 0x0031 (Java 1.5) 29>>4 belong 0x0032 (Java 1.6) 30 31 320 belong 0xcafebabe 33>4 belong 1 Mach-O fat file with 1 architecture 34>4 belong >1 35>>4 belong <20 Mach-O fat file with %ld architectures 36 370 belong 0xcafed00d JAR compressed with pack200, 38>>5 byte x version %d. 39>>4 byte x \b%d 40!:mime application/x-java-pack200 41