MacosX default library

[jean bobby]

Hi,

How to know, or is there a logic to know, if a specific library is provided on all MacosX installation by default ?

for example on my system: locate libz.dylib

/Developer/SDKs/MacOSX10.4u.sdk/usr/lib/libz.dylib
/Developer/SDKs/MacOSX10.5.sdk/usr/lib/libz.dylib
/opt/local/lib/libz.dylib
/usr/lib/libz.dylib

Since I installed xcode and some other packages, I really don't know if thoses libs where by default on my system. I need an answer to know if my program can be safely redistributed if it links with for example /usr/lib/libz.dylib

Can anyone tell me the logic ?

Thanks

PS: I'm mainly focused on libpng and libz