What kind of info are there in the first 832 bytes of .so file?

I saw many similar stuff like this:

open("/lib64/libpthread.so.0", O_RDONLY) = 3
read(3, "\177E开发者_如何学GoLF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\260W \0242\0\0\0"..., 832) = 832

What's there in the beginning 832 bytes?

If the listing above was captured at program startup, then it is likely that you are seeing the runtime loader in action, as it brings in shared libraries and resolves symbols prior to launching the program.

As for the initial contents being read, every ELF file starts with an ELF header which describes the layout and contents of the rest of the file---please see the tutorial "libelf by Example" for more information.