After having installed libpng into my computer, I've included it into my project using #include <png.h> on a Windows 7 SP1 plateform and using Visual Studio Ultimate 2013.
But at build time, I'm getting this error:
C1083: Cannot open include file: 'unistd.h': No such file or directory
How do I please to fix this? I haven't found yet any solution in the net?
The "uni" in unistd stands for "UNIX" - you won't find it on a Windows system.
Most widely used, portable libraries should offer alternative builds or detect the platform and only try to use headers/functions that will be provided, so it's worth checking documentation to see if you've missed some build step - e.g. perhaps running "make" instead of loading a ".sln" Visual C++ solution file.
If you need to fix it yourself, remove the include and see which functions are actually needed, then try to find a Windows equivalent.
If you're using ZLib in your project, then you need to find :
#if 1
in zconf.h and replace(uncomment) it with :
#if HAVE_UNISTD_H /* ...the rest of the line
If it isn't ZLib I guess you should find some alternative way to do this. GL.
来源：https://stackoverflow.com/questions/22705751/cannot-open-include-file-unistd-h-no-such-file-or-directory