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Command: htonl | Section: 3 | Source: OpenBSD | File: htonl.3
HTONL(3) FreeBSD Library Functions Manual HTONL(3)
NAME
htonl, htons, ntohl, ntohs - convert values between host and network byte
orderings
SYNOPSIS
#include <arpa/inet.h>
uint32_t
htonl(uint32_t host32);
uint16_t
htons(uint16_t host16);
uint32_t
ntohl(uint32_t net32);
uint16_t
ntohs(uint16_t net16);
DESCRIPTION
These routines convert 16 and 32-bit quantities between different byte
orderings.
The htonl() and htons() functions convert quantities from host to network
byte order while the ntohl() and ntohs() functions convert in the other
direction.
The last letter (`s' or `l') is a mnemonic for the traditional names for
such quantities, short and long, respectively. Today, the C concept of
short and long integers need not coincide with this traditional
misunderstanding. 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
gethostbyname(3), getservent(3), htobe64(3)
STANDARDS
The htonl(), htons(), ntohl(), and ntohs() functions conform to IEEE Std
1003.1 ("POSIX.1").
HISTORY
These functions appeared in 4.2BSD.
BUGS
On the alpha, amd64, i386, and some mips and arm architectures, bytes are
handled backwards from most everyone else in the world. This is not
expected to be fixed in the near future.
FreeBSD 14.1-RELEASE-p8 September 11, 2022 FreeBSD 14.1-RELEASE-p8