byteorder(3) - NetBSD Manual Pages

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BYTEORDER(3)              NetBSD Programmer's Manual              BYTEORDER(3)


NAME

     htonl, htons, ntohl, ntohs - convert values between host and network byte
     order


LIBRARY

     Standard C Library (libc, -lc)


SYNOPSIS

     #include <sys/types.h>

     in_addr_t
     htonl(in_addr_t host32);

     in_port_t
     htons(in_port_t host16);

     in_addr_t
     ntohl(in_addr_t net32);

     in_port_t
     ntohs(in_port_t net16);


DESCRIPTION

     These routines convert 16 and 32 bit quantities between network byte or-
     der and host byte order. The types in_addr_t and in_port_t are defined by
     X/Open as:

           typedef u_int32_t in_addr_t;
           typedef u_int16_t in_port_t;

     On machines which have a byte order which is the same as the network or-
     der, routines are defined as null macros.

     These routines are most often used in conjunction with Internet addresses
     and ports as returned by gethostbyname(3) and getservent(3).


SEE ALSO

     gethostbyname(3), getservent(3)


HISTORY

     The byteorder functions appeared in 4.2BSD.


BUGS

     On the VAX bytes are handled backwards from most everyone else in the
     world.  This is not expected to be fixed in the near future.

     The `l' and `s' suffixes in the names are not meaningful in machines
     where long integers are not 32 bits.

NetBSD 1.5.1                     June 4, 1993                                1