intro (3)
Leading comments
Copyright (C) 2007 Michael Kerrisk <mtk.manpages@gmail.com> %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. ...
NAME
intro - introduction to library functionsDESCRIPTION
Section 3 of the manual describes all library functions excluding the library functions (system call wrappers) described in Section 2, which implement system calls.Many of the functions described in the section are part of the Standard C Library (libc). Some functions are part of other libraries (e.g., the math library, libm, or the real-time library, librt) in which case the manual page will indicate the linker option needed to link against the required library (e.g., -lm and -lrt, respectively, for the aforementioned libraries).
In some cases, the programmer must define a feature test macro in order to obtain the declaration of a function from the header file specified in the man page SYNOPSIS section. (Where required, these feature test macros must be defined before including any header files.) In such cases, the required macro is described in the man page. For further information on feature test macros, see feature_test_macros(7).