Among the topics presented in this section are:
The header (.h) files fcntl, floatingpoint, math, langinfo, nl_types, siginfo, signal, stat, stdarg, types, ucontext, values, varargs, and wait (on the wstat page) are described.
The user environment (environ), the subset of the user environment that depends on language and cultural conventions (locale), the large file compilation environment (lfcompile), and the transitional compilation environment (lfcompile64) are described.
The macros to format Reference Manual pages (man and mansun) as well as other text format macros (me, mm, and ms) are described.
Tables of character sets (ascii, charmap, eqnchar, and iconv), file format notation (formats), file name pattern matching (fnmatch), and regular expressions (regex and regexp) are presented.
Topics concerning the Federated Naming Service (fns, fns_initial_context, fns_policies, and fns_references) are discussed.
The POSIX (IEEE) Standards and the X/Open Specifications are described on the standards page.