term% cat index.txt INTRO(3) Library Functions Manual INTRO(3)
NAME
intro - introduction to library functions
SYNOPSIS
#include <stdio.h>
#include <math.h>
DESCRIPTION
This section describes functions that may be found in various li‐
braries, 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' op‐
tion. 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 au‐
tomatically loaded as needed by the Fortran compiler f77(1). The
link editor searches this library under the `-lm' option. Decla‐
rations 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 in‐
tro(2)) is set to the value EDOM or ERANGE. The values of EDOM and
ERANGE are defined in the include file <math.h>.
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)