INTRO(3)

NAME
intro - introduction to the C libraries

DESCRIPTION
This section provides an overview of the C library functions, their error returns and other common definitions and concepts. Most of these functions are available from the C library, libc. Other libraries, such as the math library, libm, must be indicated at compile time with the -l option of the compiler.

The various libraries (followed by the loader flag):

libc (-lc)
    Standard C library functions. When using the C compiler cc(1), it is not necessary to supply the loader flag -lc for these functions. There are several `libraries' or groups of functions included inside of libc: the standard I/O routines, database routines, bit operators, string operators, character tests and character operators, des encryption routines, storage allocation, time functions, signal handling and more.

libcurses (-lcurses -ltermcap)
    Terminal independent screen management routines for two dimensional non-bitmap display terminals. (See ncurses(3).)

libcompat (-lcompat)
    Functions which are obsolete but are available for compatibility with 4.3BSD. In particular, a number of system call interfaces provided in previous releases of BSD have been included for source code compatibility. Use of these routines should, for the most part, be avoided. The manual page entry for each compatibility routine indicates the proper interface to use.

libkvm (-lkvm)
    Functions used to access kernel memory are in this library. They can be used against both a running system and a crash dump. (See kvm(3).)

libl (-ll)
    The library for lex(1).

libm (-lm)
    The math library, libm. The math library is loaded as needed by the Pascal compiler, but not by the C compiler which requires the -lm flag. (See math(3).)

libmp (-lmp)

libtermcap (-ltermcap)
    The terminal independent operation library package. (See termcap(3).)

liby (-ly)
    The library for yacc(1).

FILES
/usr/lib/libc.a
    the C library
/usr/lib/libc_p.a
    the C library compiled for profiling
/usr/lib/libm.a
    the math library
/usr/lib/libm_p.a
    the math library compiled for profiling

SEE ALSO
cc(1), ld(1), nm(1), intro(2), math(3), stdio(3)

HISTORY
An intro manual appeared in AT&T UNIX.