NAME

intro − introduction to library functions

DESCRIPTION

This section describes functions that are found in various libraries.  The library functions are those other than the functions which directly invoke UNIX system primitives, described in Section 2. 

The library to which each function belongs is indicated by the letter which may appear at the end of its manual page heading.  In Section 3, the functions are physically grouped together into the following libraries:
 

(3) and (3S)
Functions with the suffix (3) are the standard C library functions.  The C library also includes all the functions described in Section 2.  The (3S) functions make up the standard I/O library.  These functions, along with the (3N), (3X), and (3C) routines, constitute library libc, which is automatically loaded by the C compiler cc(1), the Pascal compiler pc(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 can be obtained from include files indicated on the appropriate pages. 

(3C) Routines included for compatibility with other systems.  In particular, a number of system call interfaces provided in previous releases of 4BSD have been included for source code compatibility.  The manual page entry for each compatibility routine indicates the proper interface to use. 

(3F) The (3F) functions are all callable from Fortran.  They perform the same tasks as the (3) functions. 

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

(3N) The (3N) functions constitute the internet network library. 

(3S) These functions constitute the standard I/O package (see intro(3S)) and are in the library libc, mentioned above.  Declarations for these functions can be obtained from the include file <stdio.h>. 

(3X) Various specialized libraries have not been given distinctive captions.  Files in which such libraries are found are named on appropriate pages. 

FILES

/lib/libc.a
/usr/lib/libm.a
/usr/lib/libc_p.a
/usr/lib/libm_p.a

SEE ALSO

intro(3C), intro(3S), intro(3F), intro(3M), intro(3N), 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 (domain error) or ERANGE (range error).  The values of EDOM and ERANGE are defined in the include file <math.h>. 

4th Berkeley Distribution  —  November 2, 1987