Question

I have an osx executable that runs succesfully. When I run

nm mono | grep UNIX

on it, I get these results:

     U _accept$UNIX2003
     U _bind$UNIX2003
     U _closedir$UNIX2003
     U _connect$UNIX2003
     U _fwrite$UNIX2003
     U _getpeername$UNIX2003
     U _getsockname$UNIX2003
     U _listen$UNIX2003
     U _mmap$UNIX2003
     U _mprotect$UNIX2003
     U _munmap$UNIX2003
     U _nanosleep$UNIX2003
     U _opendir$UNIX2003
     U _pthread_cond_timedwait$UNIX2003
     U _pthread_cond_wait$UNIX2003
     U _pthread_join$UNIX2003
     U _recv$UNIX2003
     U _recvfrom$UNIX2003
     U _recvmsg$UNIX2003
     U _semctl$UNIX2003
     U _send$UNIX2003
     U _sendmsg$UNIX2003
     U _sendto$UNIX2003
     U _setenv$UNIX2003
     U _strftime$UNIX2003
     U _unsetenv$UNIX2003

Since the app runs succesfully, apparently the OS is able to succesfully resolve these symbols when it loads the application. I am trying to figure out which system library defines these symbols.

One likely suspect is /usr/lib/libSystem.B.dylib, however, when running

nm /usr/lib/libSystem.B.dylib | grep UNIX

there turn out to be no symbols in there with the $UNIX2003 suffix.

I’d like to figure out where these symbols are defined, in relation to a build problem on a seperate program that does not succesfully run, but fails at runtime because it cannot find _opendir$UNIX2003.

Answer 1

See the definite discussion in this apple document, Symbol Variants Release Notes.

All these are defined in /usr/lib/libSystem.B.dylib. Note that it is a universal dylib, i.e. contains both 32 bit and 64 bit versions. On your box, you’ll see something like

/usr/lib$ nm -arch i386 libSystem.dylib  | grep fputs
000c22c0 T _fputs
000328bc T _fputs$UNIX2003
/usr/lib$ nm -arch x86_64 libSystem.dylib  | grep fputs
00000000000551cf T _fputs

The point is, there’s no non-SUS compliant versions of these functions in the 64 bit variant. So there’s no $UNIX2003 variant. I guess your linking problem is due to the supported architecture of your library.