From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4a) Gecko/20030401 Description of problem: -D_XOPEN_SOURCE is required for __USE_ISOC99 for the prototype for strtof to be defined. The man page for strtof should document this requirement Version-Release number of selected component (if applicable): 1.53-1 How reproducible: Always Steps to Reproduce: 1. man strtof 2. look for why #include <stdlib.h> isn't good enough Actual Results: nothing found Expected Results: For strtof to be available, you should include -D_XOPEN_SOURCE Additional info:
the man pages are not tied to any particular version of C. Given enough time, when gcc implements C99 by default, the macro may no longer be necessary. The info pages for glibc are always the canon source for [the particular glibc] implementation specific details.