NAME
htonl, htons,
ntohl, ntohs —
convert values between host and network
byte order
LIBRARY
library “libc”
SYNOPSIS
#include
<arpa/inet.h>
or
#include <netinet/in.h>
uint32_t
htonl(uint32_t
hostlong);
uint16_t
htons(uint16_t
hostshort);
uint32_t
ntohl(uint32_t
netlong);
uint16_t
ntohs(uint16_t
netshort);
DESCRIPTION
These routines convert 16 and 32 bit quantities between network byte order and host byte order. On machines which have a byte order which is the same as the network order, 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
STANDARDS
The byteorder functions conform to
IEEE Std 1003.1-2001 (“POSIX.1”).
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.