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INTRO(3)                   Library Functions Manual                   INTRO(3)



NAME
       intro - introduction to library functions

SYNOPSIS
       #include <&lt;stdio.h>&gt;

       #include <&lt;math.h>&gt;

DESCRIPTION
       This   section  describes  functions  that  may  be  found  in  various
       libraries, other than those functions that directly invoke UNIX  system
       primitives,  which  are  described in section 2.  Functions are divided
       into various libraries distinguished by the section number at  the  top
       of the page:

       (3)   These  functions,  together  with  those  of  section 2 and those
             marked (3S), constitute  library  libc,  which  is  automatically
             loaded  by  the C compiler cc(1) and the Fortran compiler f77(1).
             The link editor ld(1)  searches  this  library  under  the  `-lc'
             option.  Declarations for some of these functions may be obtained
             from include files indicated on the appropriate pages.

       (3M)  These functions constitute the  math  library,  libm.   They  are
             automatically  loaded  as  needed by the Fortran compiler f77(1).
             The link editor searches this library  under  the  `-lm'  option.
             Declarations for these functions may be obtained from the include
             file <math.h>.

       (3S)  These  functions  constitute  the  `standard  I/O  package',  see
             stdio(3).   These  functions are in the library libc already men-
             tioned.  Declarations for these functions may  be  obtained  from
             the include file <stdio.h>.

       (3X)  Various  specialized  libraries  have  not been given distinctive
             captions.  The files in which these libraries are found are named
             on the appropriate pages.

FILES
       /lib/libc.a
       /lib/libm.a, /usr/lib/libm.a (one or the other)

SEE ALSO
       stdio(3), nm(1), ld(1), cc(1), f77(1), intro(2)

DIAGNOSTICS
       Functions  in the math library (3M) may return conventional values when
       the function is undefined for the given arguments or when the value  is
       not  representable.   In  these  cases the external variable errno (see
       intro(2)) is set to the value EDOM or ERANGE.  The values of  EDOM  and
       ERANGE are defined in the include file &lt;math.h&gt;.

ASSEMBLER
       In  assembly language these functions may be accessed by simulating the
       C calling sequence.  For example, ecvt(3) might be called this way:


              setd
              mov  $sign,-(sp)
              mov  $decpt,-(sp)
              mov  ndigit,-(sp)
              movf value,-(sp)
              jsr  pc,_ecvt
              add  $14.,sp



                                                                      INTRO(3)