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