Hi All, i have been reading Unix filesystem - evolution, design and implementation by Steve D. Pate and it provides a simple file system source code for learning and playing with. On the header file, it defines the fs magic number as #define UX_MAGIC 0x58494e55 1. which means, will it assign this magic number to ALL files created on this sample fs? That can't be so. Otherwise, why we need to define a magic number? 2. I assume, magic number will be assigned to files by the tools which we use to create the files(like vi, cat, etc). Is this correct? 3. It seems, windows files also have the magic numbers. let's say I copy some files from windows to Linux. We should have the common magic numbers between different Operating systems, so there won't be confusions. I mean, is there any standards common for all os's files magic numbers?!? Best regards Sekar