INTRO(3)                    Linux Programmer's Manual                   INTRO(3)

       intro - introduction to library functions

       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).

       Certain terms and abbreviations are used to indicate UNIX variants and
       standards to which calls in this section conform.  See standards(7).

   Authors and copyright conditions
       Look at the header of the manual page source for the author(s) and
       copyright conditions.  Note that these can be different from page to

       intro(2), errno(3), capabilities(7), credentials(7), environ(7),
       feature_test_macros(7), libc(7), math_error(7), path_resolution(7),
       pthreads(7), signal(7), standards(7), system_data_types(7)

       This page is part of release 5.13 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at

Linux                              2020-11-01                           INTRO(3)