Maris Labs has re-released the eXtended C Standard Library (or xstdlib).
"The xstdlib (eXtended Standard Library) is a library that ports many essential or miscellaneous high-level language functions (like in PHP, Python or Perl) to C or any functions that are of common use to C developers."
Download here: http://marislabs.org/ext/apps/?p=desc&app=23
OR
Download here: https://sourceforge.net/projects/xstdlib/