I have a third party OS X dylib that I'm using in my app and don't have easy access to its creator. I'd like to determine if it was linked with -flat_namespace. Is that possible? If so, how?
Run otool -hV on the library. If you don't see TWOLEVEL, then it was linked with -flat-namespace. For example:
twolevel.dylib:
Mach header
magic cputype cpusubtype caps filetype ncmds sizeofcmds flags
MH_MAGIC_64 X86_64 ALL 0x00 DYLIB 8 672 NOUNDEFS DYLDLINK TWOLEVEL NO_REEXPORTED_DYLIBS
versus
flat.dylib:
Mach header
magic cputype cpusubtype caps filetype ncmds sizeofcmds flags
MH_MAGIC_64 X86_64 ALL 0x00 DYLIB 8 672 DYLDLINK NO_REEXPORTED_DYLIBS
来源：https://stackoverflow.com/questions/2553530/how-to-determine-if-an-os-x-dylib-was-linked-with-flat-namespace